General Vista Troubleshooting

Ever had the system reboot with a blue screen flashing in front of you for a fraction of a second? Annoying and/or cryptic error messages popping up with every click? The following links may help to solve your problem. Check them out before posting a thread as they may answer your questions.

General sequence for performing troubleshooting

How to check the Reliability Monitor for errors

How to generate a system health report

How to troubleshoot common Stop Errors (Blue Screens)

How to check system files in Vista

How to perform a startup repair

How to perform a full system repair

Troubleshooting Sleep Issues

Suggestions to Improve Performance

Some thing I didnt see mentioned in the above links.
If you find that your system is having Stop Errors (Blue Screens)
It is important to get the error message that Windows will provide.
Unfortunatly Windows isnt set to give this info. but with a small adjustment it will.
Open the control panel and double click system.
Then open the Advanced System Settings on the left.
Then open the Advanced tab then Startup and Recovery settings.
Uncheck the Automatic Restart box and hit OK.

If your system encounters a BSOD again it will wait with a error code that you can use to help find the trouble.

Below is a link with additional error codes that could be helpful.
http://kadaitcha.cx/vista/kb/stop_error.html

FAQs
http://www.petri.co.il/vista_tips.htm

DO NOT use passwords if you dont absolutely need them. When you lose them you will find it very difficult to get help.
You say it is your system, but how is one to really know?