why user profile corrupt in windows 2000 ?

It could be your logged on as administrator and not your account profile. You can check by going to your control panel and look at your user account. Or open the task manager and look at the current user logged in.

Also you can try going to "www.pcpitstop.com" and have them test it for free.You can test anonymously if you wish. It may be ad-ware or spy-ware corrupting your computer. Once the test are complete. the results page will come up. Read through the text til you see "test details" click on this. now you can see all the results and running programs. I recommend printing a copy for reference.

The site will give some quick fixes but to remove any spy-ware or ad-ware go to the start button, run, type in "msconfig" select diagnostic startup.

After up and running go to the c: drive/ folder/ file and delete. (Location can be found by looking at above test result print out.)