Recently i had installed Windows 7 on my machine. Now the problem is that my Explorer show 2 thread for svchost.exe with 100% CPU usage. In that first one shows as ntdll.dll!RtlIsCriticalSectionLockedByThread+0x9f0 (about 50% CPU), while the second shows as ntdll.dll!RtlRegisterThreadWithCsrss+0x197 (about another 50% CPU). On my system, the Process Explorer is been showed under SVCHost.exe. In order to speed up the computer I kill the thread but from then on programs do not load correctly when they attempt to run the same line of code. So, can any one tell me that why does svchost.exe shows 100% CPU ntdll.dll on Windows 7? Any one has any idea about it? Kindly help me out to resolve the above issue. Thanks.