|It is normal for games to utilize 100 percent of the cpu. Some games use less than 100, so keep that in mind. However, if another program running in the background is eating up precious cpu time, games will often lag. Open up task manager and look under the processes tab. Look for processes that are using abnormal amounts of cpu time (anything above 10 percent would qualify). If you find one or more, disable them if you can. You can use msconfig.exe to disable certain processes from loading with windows. There is also a cool little utility called ccleaner, which has a tool built in that does the same thing. |
Of course, there are many other variables that could be causing your problem. Since you mentioned you recently reinstalled windows, you may not have installed the proper drivers for all of your hardware. It could also be a software related issue, e.g. some anti virus programs can interfere with games too, causing them to slow down. Task manager is your best bet right now, have a look at the number of processes in there, and the amount of cpu time they are using.
Post your complete system specs in the future, it helps everyone in this forum.
Edit: Multi-core cpu's may not approach peak cpu usage while playing games due to the additional cores. My original explanation deals exclusively with single core cpu's, i.e. while playing games, most single core cpu's will use close to, or 100 percent of the cpu.