Windows becomes INACTIVE in < 1 minute

All,
My window goes inactive every 30 seconds or so. i have to click on the window to make it active. this is very annoying if i am typing. Other than for browsing, I can hardly use my computer for doing any serious work.
My cousin was using this computer for the last 1 year. He says he has had this problem for about 1 year (... ??). ( this window went inactive 7 times by the time this mail was close to completion.
I have searched this forum but could not find anything relevant. If I overlooked some post, I offer my apologies in advance..
Pl. help
Thanks in advance
regards
JT

System details:
I have windows XP with automatic updates(SP2) on my P3 compaq system (1.6ghz).
I have symantec firewall, antivirus (corporate edition from my school). I also have adaware, spybot, ewido installed in my system along with Microsoft anti-virus (giant). I update my symantec stuff every day plus run the anti-virus stuff every nite. This is on my home computer.
I use firefox as my browser

 

download tweakui powertoy-navigate in tweakui to general>focus>check prevent application from stealing focus.

 

Your suggestion worked. Thank you very much... u are DA MAN!!!!!!!
I did a google search but had failed to find an answer but did find that quite a few folks had similar problems.
U really are great !!!!! outstanding... I really dont know how to thank you...
really appreciate ur help

regards
JT

PS:
Do you know of any applications that steal focus.. knowing those apps... would be enlightening for dumbos like me.

 

welcome junk_trash1
I cant say what is stealing focus,but maybe you can find it yourself-dont have to undo your twekui setting.Just see if anything on your taskbar blinks or changes color.It may also be one of your apps in the tray.It maybe one of your apps may be malfunctioning or some spyware(in which case you wont find it that easily).Anyway keep your system clean and you should be fine.If you are concerned visit the spyware section.

 

Try

Process Explorer 9.12 from

http://www.majorgeeks.com/download.php?det=4566