Microsoft has sole ownership of MS Word, a program that has been using the .doc extension for many years. They have the authority to develop this type of file as they see fit. In their latest versions of Word for 2007 and 2008, they changed the default output file of MS Word from DOC to DOCX. Older versions can access this new format by downloading and installing a compatibility pack.

The .doc format for word processing is among many similar file types with different extensions but with the same functions for manipulating word processing features. These other extensions include:

• .TXT;
• .rtf;
• .html;
• .odt;
• .wpd; and
• .pdf

Programs like Open Office, WordPerfect, and Adobe are needed to open, create, and edit these types of files.

Document files allow the user to input data, images, tables, and other elements to enhance the presentation. The only problem with this format compared to other file types, like .pdf for example, is its ability to be easily edited. This means that anyone viewing the file can accidentally change it. Also, this file format may be opened by other programs, but it does not guarantee that what you see in the Microsoft Word application will remain the same when you view it with another program. However, it is still preferred by most of the computer users for its ease of use and features.

Files with the DOC extension are also susceptible to viruses, but good antivirus software can fix this. Another problem is that .doc files can be corrupted, unreadable, or damaged due to spyware, adware, and malware. These cases will prevent users from properly opening DOC files. This is when effective registry cleaners come in handy.

A registry cleaner is a program that cleans the registry. The Windows registry is always flooded with junk data, information that was not removed from uninstalled programs, wrong file association, and other misplaced entries on the computer. These neat little system software tools are pretty common nowadays and you can find quite a few good ones on the internet. The good ones give you the option to maintain, clean, update, backup, and scan the System Registry. When it finds supposedly unwanted items in it, the registry cleaner lists them and recommends the user to delete or repair these orphaned entries and corrupted keys.