Sometimes Lost Tab/Esc in Virtual PC

I've experienced this problem several times. At first, I just restarted and usually solved the problem. But today, it didn't solve my problem, so these are the possible solutions:

• Delete Options.xml file located in %AppData%\Roaming\Microsoft\Virtual PC folder
• Add new Path Rule to the "Local Security Policy\Software Restriction Policies\Additional Rules" with value "%appdata%\microsoft\virtual pc\vpckeyboard.dll" and Unrestricted security level

I've tried the first solution. Both solutions require you to shut down your Virtual PC including the console.