Windows Search Woes

I am hoping that someone can make a suggestion. Our school is running windows 7 and I have noticed that quite often our group policies are not applying all the time. I have also noticed this seems to happen most when the CPU is busy. Why is the CPU busy you ask? Well it appears theat the windows search feature is eating between 80 - 100% CPU. I have tuned the search service off and GP seems to behave a lot more reliably but then users can't search or find anything / including Emails.

Any suggestions?

Take a look at this article as i think it might help hopefully CPU usage running at 100%

Thanks for the prompt replies. We have around 400 workstations and it appears to happen from time to time on all of them. The index service is also extermely heavy on our main data server also. [In fact I threw a lot more virtual memory and CPUS at it just to help it cope a little better].
I have also read there is an issue with windows search and XML files [in particular Itunes] Is there a way to change what the search indexed via group poicy?

I wasn't aware that you can index a network drive. The server is ONLY indexing the DATA folder and the Windows 7 machines just have the defaults set, ie the c: drive.

I just logged to a couple of the machines to see what they were indexing. I can see entries for internet explorer for each user. I can also see that it has entries for offline files\username which is a little odd as offline files are disabled. I can also see that it is indexing c:\users.

Domain with 3 x Server 2008R2 64bit active directory