Please provide more info about your environment (e. g. guest os, VMWare version).
If you uninstall Returnil and NOD32 (and other security apps except CFP) does it make any difference?
Thank you for responding

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Host OS - Windows XP2 with all patches
Guest OS - Windows XP2 with all patches
VMWare Workstation v5.5.6
Returnil not installed in the virtual machine.
I didn't try to uninstall NOD32 in virtual machine but perhaps I will soon, just to rule it out as a possibility.