Don't let it update your definitions! You'll get horked for sure.
For those affected, the problem is that Macafee ends up deleting the svchost file from the WINNT\system32 directory.
If your taskbar is missing and your desktop just doesn't look right, you have been affected by the Macafee definition update that has deleted the svchost.exe file from the WINNT directory.
This is the fix:
My company was hit by this and this has been the fix for my desktop and many others.
Thanks for that. I had a mystery case come in late this afternoon, and this pretty much describes it. I’ll fix it when I get in tomorrow AM.