COM (Component Object Model) is Microsofts component software architecture developed mainly for Windows. It is the basic foundation upon which OLE and ActiveX are based. It provides a method to reuse code without any need of recompilation. In COM, a component is a platform-specific binary file that can be utilized easily by compliant applications as well as other components. Programs incorporating the services of a component do not require an access to its internal data structure; however, it contains pointers for its standardized interface. As a result, the components can interact with each other irrespective of the manner in which they work or the language in which they are written.

The COM/ActiveX section of the registry may include invalid entries that can induce issues like system crashes, application failures, or errors while opening documents.

PC Optimizer Pro scans the Windows Registry for all com/ActiveX references to ensure their physical path is associated with the registry key. In case the scan finds that the path is defective, the product removes its reference from the registry.

When you install a new piece of software onto your system, the software stores a variety of information in your Windows registry. But on uninstalling the software from your PC, some keys stay back in your PC.

These extra registry entries are not associated with any installed software, and therefore take up space in your registry. Thus, these missing file references and surplus registry entries tend to make accessing registry keys, which are actually used by installed programs on your computer, slower. It eventually results in causing the programs you are trying to run take longer than usual to respond.

PC Optimizer Pro will search uninstall registry areas to confirm that a valid file path exists to the files listed. If the uninstall path to the file does not exist, the items placeholder in the registry will be removed. This creates free space in you registry, making it quicker and easier for your other programs to access the settings they need without problems.

Invalid font entries occur when fonts are removed from the system without the registry being updated accordingly. This can cause program crashes, especially in word processing applications.

PC Optimizer Pro will verify the existence and validity of all installed Fonts.

Shared DLLs are files used by multiple programs for performing various functions. DLL stands for Dynamic Link Library. These files contain instructions and codes to perform common tasks such as printing. This allows software developers to add printing functionality to their programs by referencing the DLL rather than creating their own complex set of instructions to accomplish the same task.

The problem with shared DLLs is that if one goes missing or corrupt, the programs will encounter DLL errors. This can happen when you uninstall a program and remove all of its related DLLs (even the shared ones) or when you install a new program that uses a different version or release of the same DLL as other programs. The different version may not be compatible with other programs that use the DLL in question. When this happens, you will get DLL errors.

PC Optimizer Pro will verify all Dlls used to run Windows and installed applications.

These are typically paths that are not removed when programs are uninstalled or paths which are written to the registry by applications and where the physical path is removed or changed, leaving an invalid application path in the registry.

Incorrect path information in the registry may cause programs to malfunction.

PC Optimizer Pro will remove all such paths which create invalid entries in the PC.

When a program is installed it makes entries relating to the help files associated with it in the registry.

If a help file is deleted or moved from the folder where it was originally installed, it results in invalid registry entry.

PC Optimizer Pro will verify the existence and validity of all help files and supporting resources.

There are the programs which are scheduled to be launched at Windows startup.

The programs that are actually removed from the disk result in creating invalid registry entries and sometimes windows error messages displaying invalid program paths.

PC Optimizer Pro will check all applications that are loaded at Windows startup.

Scans everything in your registry section LOCAL_MACHINE for all user changes and will scan for all invalid changes as well.

These entries may cause errors in the programs and make your PC work slower.

PC Optimizer Pro will check clean deep-rooted registry errors.

There are some program shortcuts created by certain applications when they are installed on a PC and are linked to the main program.

Invalid shortcuts create registry issues that point to paths which do not exist on the disk.

PC Optimizer Pro will validate all program shortcuts and application links.

In Windows, a file type is associated with certain program and the information about this mapping is stored in the registry.

The File Association section of the registry can contain invalid file associations. If a file type is associated with a program that does not exist then it shows up as an irregularity.

PC Optimizer Pro will check for all file association issues in the registry.

All programs have different File Extensions. On installing the program on your PC, they create registry keys which will help that program to execute.

On uninstalling that program from the PC those keys will remain in the PC, resulting in invalid keys (i.e. keys not associated with any program).

PC Optimizer Pro will validate all file types associated with the Explorer Shell.

Check all custom controls and application classes.

The hard disk on your computer has a limited amount of space. If you run out of space on your hard disk, your computer may crash, lockup, or even fail to start up.

The more the number of files on your hard disk, the more will be the time needed for it to access files when the computer will be in use. Also, the performance of your computer will slow down with increase in the amount of data stored on your hard drive.

Removing trash files from your computer would help you regain valuable disk space on your hard drive. Also, it will provide more space on your hard drive for new programs and files such as pictures, movies, etc. Regular removal of garbage files from the computer will also help in avoiding various issues caused due to low disk space.

Whenever you run a computer program, a file is created for keeping a track of all interim results. It is known as temporary file and is deleted once the execution of program is complete.

However, some programs build temporary files and then just leave them behind without deleting. Such a situation can arise in case the program is crashed .The temporary files left behind in such cases can pile up on your hard drive over a period of time, thereby consuming a lot of disk space.

A folder on the hard disk where Windows stores all the files you have deleted is termed as the 'Recycle Bin'. Till the time you empty the Recycle Bin, the deleted files can be restored.

Whenever you run out of disk space or intend to clean the contents of your hard disk, it is recommended that you empty the Recycle Bin. Or else, it is all right to leave any deleted items in the Recycle Bin if you might need to restore them later.

Every time you use the Start Menu's Run command to launch a program, that program is added to a history.

Windows keeps a track of the most recently used files in a folder called 'Recent Documents'. This property of keeping a record of the recent documents tends to create a threat to your offline/online privacy since anyone accessing your computers can access these files as well.

A Program Shortcut is a small file representing the name of a parent program file that the shortcut targets. In addition, the shortcut may indicate a set of characteristics that will be passed on to the target program when it runs. A shortcut is generally displayed on the desktop or Windows Start Menu.

The details of a program, including the date and the number of times the program has been used, are recorded in an encrypted database each time the user runs a program using the start menu. By this procedure, Windows keeps a track of the programs files, folders, history, etc.

Start menu order history deletes the history stored in the start menu for all programs. Due to this operation, the listings for all applications in the start menu are affected.

The details of whatever goes in and out of a particular server are recorded in a file known as 'log file'. The concept and application of a log file is similar to that of a black box used in an airplane; keeping records of everything happening around so that an analysis can be done in the event of an issue. The information is often records chronologically, and is stored in the root directory. Occasionally, it can also be located in a secondary folder, on the basis of its dependence and synchronization with the server.

A 'Pagefile' is the reserved quota of a hard disk which is used in the form of an extension of Random Access Memory (RAM) for information/data in RAM that has not been used of late. A typical 'Pagefile' can be read from the disk as one adjacent portion of data, and therefore faster as compared to re-reading data from various original locations.

A temporary folder or directory is used for storing temporary files. In general, operating systems tend to delete the contents of this temporary folder automatically at the time of startup or after certain regular interval.

Due to security reasons, it is recommended for users to have their own temporary folder, seeing a number of incidents happening over the years due to security vulnerabilities associated with temporary files. Moreover, having temporary directory is advisable as incorrect file permissions can often lead to security threats.

By deleting temporary files, the users can reduce the amount of storage space used by the entire directory. But on multi-user systems, removing files this way can often result in unwanted removal of active files, thereby disrupting the activities of any particular user. To avoid such complications, certain space-reclaiming processes are used to remove only inactive or "old" files which have not been used (read or modified) by the user in recent times.

While downloading a file from Internet, if we "Run" the file rather than saving it, the file is automatically saved in Windows Download Temp folder.

Windows Update is downloaded to a temporary folder in the root of the drive having the maximum free space when the download is done.

The browser cache, also known as the temporary Internet files folder, stores files from the web sites you have visited using your browser. The most important reason behind web browsers maintaining a cache (generally meaning 'hidden memory') of files is to enable a faster loading and display of web pages when you open the same web site the next time. As a result, when you open the same site for the second time, the files are loaded from the cache folder of your browser (maintained on your computer), rather than retrieving the files from the online web server (the computer which actually hosts the particular web site). Thus, you get a faster loading and display of the web page.

Over a period of time, the cache folder grows in size large enough to occupy a massive amount of space on your hard drives, thereby resulting in wastage of valuable disk space. Also, too much data on your system makes it run slow, which can result in unwanted hangs and unresponsive Windows. There are a number of web sites you may not visit soon again, and storing their cache files is nothing more than wastage of hard disk space and memory.

A cookie is a message sent by a Web server to a Web browser and is generally stored by the browser in text files. The same message is sent back to the web server every time the browser tries to open a particular page from the web server.

The main idea behind using cookies is to recognize the users of a web page so that web servers can prepare a potentially customized web page for any particular user. When you visit a web page by the means of a cookie, you are generally asked to fill out a form asking for general details such as your name, interests, etc. The information gathered by the form is then sent to your Web browser in the form of a cookie which it stores for later use.

When you visit the same web site again, the cookie is sent to the web server by your browser. The web server makes use of the stored information to display a custom web page that will potentially be the most relevant for you. For instance, rather than displaying a simple generic welcome page, the web page might present a welcome page carrying your name on it.

Though cookie files are very small in size; on regular usage, they tend to build up into massive cluster of files occupying too much disk space. It leads to slow down of your computers performance. At the time when a large number of cookies accumulate, those unwanted files can cause your system to run slower than usual. It is recommended that you delete cookies periodically to ensure you get sufficient speed and performance of your web browser. Also, stored cookies have your personal information and passwords recorded within, which can leak your confidential information, and therefore it is recommended that you delete cookies regularly.

In web browsers, auto complete is done in the address bar (using items from the browser's history) and in text boxes on frequently used pages, such as a search engine's search box and signup forms. Auto complete for web addresses is particularly convenient because the full addresses are often long and difficult to type correctly.

AutoComplete feature stores the history of details you enter while filling a variety of forms on the web, including registration forms, etc. Deleting AutoComplete forms on a regular basis will ensure there's no violation of your personal information by unauthorized users. In order to make sure your personal information, including business codes, financial data, etc. on filled forms doesn't leak out without your permission; it is recommended that you clean your browser's AutoComplete history periodically.