I'm running VMWare Worstation 7 with Windows 7 x64 as guest, Windows XP x64 as host. Inside the guest I run a long-running console application, which prints out progress messages with timestamps on them. Sometimes I leave it running for several hours while I lock the host OS and don't touch the computer at all. When I come back I find that some time after I left it seems to have paused and automatically resumed: the console app hasn't made much progress and there's a large time gap in its progress messages.
There's nothing relevant in the host event log, but in the guest Application event log I can see these messages around the time I left:
A request to disable the Desktop Window Manager was made by process (VMware Tools Service)
The Desktop Window Manager was unable to start because composition was disabled by a running application
And later, around the time I returned, this shows up in the System log:
The system time has changed to 2012-01-12T06:36:46.921000000Z from 2012-01-12T03:18:19.953079000Z.
That seems to support my theory that it's VMware doing something and not Windows itself. The question is: how do I stop it doing that? I want my application to continue running. By the way, the power options are set to never sleep in both guest and host.