Unusually high CPU Usage

[ashu_dps]

Hi

I have an year and half old Dell Inspiron E1505 with Intel T2300 Core duo processor , 1.5 GB ddr2 RAM(1 GB @667 and 512MB@533Mhz, 1GB stick added recently after removing another 512MB stick), Ati X1400 and a 80 GB 7200 RPM HDD.
Earlier my notebook used to run all the games quite fine for hours at stretch but now if i play any game for 2-3 hrs continuously then the CPU usage shoots to 100 % and game starts lagging and finally stops and even after exiting from the game the problem doesnt resolves easily and i have to force restart though sometimes it resumes after lagging badly for about 3-4 minutes.
Used XP n Vista both. Even reinstalled Vista from image(Used to work fine earlier)


What can be the problem ?

Had to retire my laptop from our gaming party this weekend!!

 

[ashu_dps]

Eh....... No help ?????????

 

[ilugd]

you may have to do a fresh install. If you are using pirated games, there may be some spyware or malware or maybe even viruses in that. Update all drivers. Before going for reinstallation, just run a complete av and antispyware scan. You say cpu usage is 100% even after the game ends. Which process is that?

 

[NucleusKore]

^+1 Is your Windows original?

 

[ashu_dps]

Uhhhh.... thanks for ur efforts to help me but i'm atleast this much experienced to know if the games are infected or if something is wrong with my OS.

BTW i have a Dell Inspiron, which got an original Windows and Upgrade to Vista Ultimate !