A client brought in a brand new Dell 1545 laptop with Windows 7 Home Premium X64 preloaded. It also had McAfee pre-installed. I removed McAfee and installed a free copy of Avast Home and after the reboot Avast comes up with the initial screen, but eventually Explorer stops responding. The first symptom is when I try to open the Control Panel ... freeze, can't click on anything. Just to be sure I waited 20 minutes but it never "unfroze". I can CTRL-ATL-DEL and kill explorer, and after it reloads everything appears to run without freezing initially, but if I used the computer long enough, I get either a crash or a freeze of explorer.
I uninstalled Avast and reinstalled, didn't help. Ran the McAfee uninstall tool (MCPR.EXE) to clear out all traces of McAfee Security Center, rebooted, installed Avast, freeze of explorer after reboot.
Since this was a client's computer I didn't want to take a chance and trash the installation of Windows 7 by doing more installs and uninstalls to track down a solution, so I gave up and installed AVG Free, which ran fine.
I personally have AVAST running on a test system running Windows 7 Ultimate (Microsoft's time-limited demo that will expire next year) but it's only X32, not X64. I'm wondering if this problem is caused by the OEM version of Windows 7 X64 that Dell is using or something to do with McAfee Security Center that is being preloaded on these computers. The problem *IS* real, however. Would be nice to know what is causing it.
Chuck