Though its not a bad idea to reformat your HD every year or so. Cant hurt, as after a year, there will be enough crap on it that u dont want to sink a ship. I personally defrag every month and reformat once a year
I agree with dhw200 about doing a regular disk defrag on your hard drive. As far as formatting, all you have to do is reinstall the windows operating system using your Windows CD. Make sure you have the authentication code handy or you won't be able to install it.
Boot your computer with the Windows CD in the drive. You'll be prompted to press any key to boot from the CD. Just follow the instruction from there. At some point though you'll be prompted to install from scratch or repair your existing windows. You want to select install a fresh copy of windows.
I recommend doing a disk cleanup and defrag after a complete install because the installation process copies and deletes a bunch of temporary files.
WOW!, there was some really bad english in my last post.....LOL. Ok guys just before i Re-Format what should i know? I've never done this before so do i lose programs, like x-fire and such. And what about things i have saved, gone too? Will i have to re-install everything on my computer again? Thanks again guys
Reformatting essentially will wipe your drive (the partition) completely clean. You will have NOTHING left on the drive/partition you reformatted.
If you are going to reformat, make sure you have up-to-date backups of all documents, pictures, music, emails, logs, saved-game files, etc. Make sure you have all installation disks you need because you WILL need to reinstall everything.
By the way, most major operating systems have options to reinstall the actual OS without reformatting...basically replacing all the system files and nothing else. I've seen those fail before, so if your system seems corrupted, beware, but in almost every situation that won't happen.
On the more positive, because you're wiping everything clean, all viruses, spyware, adware, other malware, and the general clutter that Windows seems to accumulate....will be GONE.