I have read that there is a documented problem with McAfee and the Windows Seven Search Index function, and I am experiencing that same problem on my machine.
Can any of the community moderators let me know when this problem will be fixed? This should be a definite priority for the development team.
We are working on a solution/ work around to get this one sorted out. In the meantime please continue in this thread where we are dealing with this issue. Re: Auto update to Security Center 2010 kills Windows 7 search
Locking thread for duplication
McAfee Online Community Moderator