The 50% cpu usage means that there is a program running in the background that is using 50% of your cpu power. It should alway's read 0% in your task manager.
Go back into task manager>crlt>alt>del, and you should see what program is using up your cpu power and memory. In the lower left it should say 0%. If it say's 50%, turn off the resource hog. It should always say system Idle process (under cpu) 99%. This is normal, but look at what other program is running under cpu!!
hey whats up guys i think i might have a major problem on my hands here. I have a AMD X2 4800+ CPU and after CTRL ALT deleting to kill a program that was flipin up i noticed my CPU usage was always 50 percent and no programs or ne thing were running. Like it said 51 percent then 52 percent maybe 53 percent but then jumps back down to 50 percent but it never goes below 50 percent so im thinking maybe my CPU is broke and only one CPU is working giving me the half cpu usage. But i dont know what do you guys think?