[CaptainHaplo]

A reformat is necessary. The last OS that was truly "movable" by moving your hard drive with reasonable success was win98. W2k introduced a much more robust - ie "thicker" - HAL that does NOT like to be moved. *HAL being Hardware Abstraction Layer*

This results in BSOD/Stop errors on boot in most anything 2000 or higher when the MB is different. While there is the outside chance it will boot, the guys above are dead on, your going to have so many failed to load drivers for devices and such your going to end up spending more time trying to sort it all out vs just a clean install and then adding in your favorite games/apps.

If you do reformat - use your current drive as a "backup and storage repository". Do it smart - things like download the appropriate service pack for the OS (always get the redistributable version) so you don't have to have open vulnerabilities while your updating the os. Go to the website of your antivirus make and get the manual update files to current. Same with drivers for your audio and video, as well as MB bridges if needed. That way - when you do rebuild - if your drive has either a storage partition with all this on it - or its all on a true second drive - your install and updating wont take as long.

Edit - another plus is the files run locally much faster when you don't have to wait on dl'ing them - so the rebuild is much faster.

Don't forget stuff like the Office SP if you use it, etc. The more you dl now and have available, the faster your rebuild will be when you do it.

Always do your install with the network cable unplugged (unless your doing a remote install) - so that open vulnerabilities are not exposed. With all the updates stored locally, you can have your OS up to date, your antivirus/firewall installed and fully "patched", etc before you plug in the cable. To many people don't realize that it doesnt take long for an "open" or default install machine to be seen and often attacked if its internet connected - update and secure yourself FIRST!!!