svchost.exe + NTDLL.DLL Causing high CPU Usage

Thanks Jacee for replying!
I did scan the excel files for malware. They were clean.
I did have all the Office critical updates installed in Windows Vista x64.
Now, Windows Update got caught in an endless loop suggesting to install a 125kb MS Office 2007 sp1 and installing it repeatedly.
Regards

Hello!
It looks like Windows Defender service causes the high CPU usage by svchost.exe in Windows 7 x64 in several hours of Windows usage. Windows Update installed the Windows Defender.
Regards

I bought Kapersky,and I did find loading files very slow.I think thats why it has a good rating.I think any AV that scans everything realtime for as long would be as good.I know alot of popular av's use Kapersky engine.I find it quite fussy when it comes to settings...don't use the blocklist,it blocks too much unless u use ur own lists.Even with Heuristics off it does the same.Also has high cpu usage.Thought i would say this as it's mentioned a few times.

It is completely gone. The issue is 100% related to Kaspersky. Ever since removal. Nothing. No spikes anymore. Thanks a ton people

thanks for the confirmation about kaspersky. i am having the same problem, every other forum i visited said that this problem is related to the "enhancements" with the audio engine of the OS. i recently installed kaspersky 2010 on my x64 win 7 ultimate(as i got it for free from houseparty lol), i'll remove it too and post here back if the problem is solved. although kaspersky says it is compatible with x64 version of win 7, it is installed in x86 folder of program files and the process(avp.exe) is also 32 bit,so i am guessing the guys at kaspersky are just trying to save their ass by saying its 64 bit compatible.