For testing purposes, it's best to install Windows "clean".
This is, basically, installing it the way that Microsoft intended (using drivers from Windows Update).
This procedure is for Windows 7 and Vista.
You will need your installation/recovery DVD(s) before you start. Once you wipe the hard drive there's no going back!!!
1. Backup all your data.
This will wipe everything off of your hard drive, so anything that you want to keep will need to be saved elsewhere.
If this is due to an infection, remember to scan the data with another system's current antivirus in order to locate and remove any malware.
Disconnect any additional hard drives (internal and external) that you may have installed. This may break any multi-boot setups that you have, so be prepared to conduct recovery operations on them once you're done. Don't forget that, if this is due to an infection, the additional hard drives may be infected also.
2. Connect the system to the internet (if the system says disconnect from the Internet, then do so).
2½. Make sure that you've run hardware diagnostics on the system, as installing Windows on "borked" hardware isn't a real good idea.
Free diagnostics here: Hardware Diagnostics
At a minimum, you must have run these bootable diagnostics (they work outside of Windows, so Windows doesn't have to be working): Initial Hardware Diagnostics
3. Use one of these free utilities to wipe the hard drive clean:
KillDisk ( Freeware Download Active@ KillDisk
DBAN ( DBAN Download | Darik's Boot And Nuke
This will also delete any recovery partitions on the system - so the installation/recovery DVD's are essential!!!
4. Install Windows by booting from the installation/recovery DVD - DO NOT tweak any settings!!!
5. Visit Windows Update and get all updates
6. Check Device Manager for any unknown/disabled devices - if there are unknown/disabled devices, fix them with the latest drivers from the device manufacturer's website (not the PC Manufacturer)
7. Visit Windows Update and get the Service Packs for your system. (usually under Important Updates).
Read these notes for installing Windows 7 SP1
: Learn how to install Windows 7 Service Pack 1 (SP1)
and Steps to follow before you install Windows 7 SP1 and Windows Server 2008 R2 SP1 from the Microsoft Download Center
Read these notes for installing Vista SP1
: Learn how to install Windows Vista Service Pack 1 (SP1)
Read these notes for installing Vista SP2
: Learn how to install Windows Vista Service Pack 2 (SP2)
Search Google/Bing for installing other OS's Service Packs.
8. Visit Windows Update and get any other available updates
9. Download, install, and update a free antivirus so you don't get infected while testing ( Free AntiVirus
10. Test to see if the problem remains.
If the problems persist
, then the problem is most likely with your hardware.
If the problems are gone
, then proceed with installing the latest version of your favorite programs, testing after each one for errors.
If you have an Asus motherboard, check the date on the C:\Windows\System32\driver\ASACPI.sys file. 2004/2005 is a problem, 2009/2010 is OK. Updates are available at the Asus support website.
If you have a Sony system, make sure that you DO NOT have the 2007 (or earlier) version of the Sony Firmware Extension Parser (SFEP.sys). Update this driver immediately!!!