Error in GVC Installer
Installed GVC 18.104.22.1681 over 22.214.171.1248 version on Windows 7 64bit. The installer asked for a reboot after installation so I did. This is the only software added/removed in the recent past. After the reboot I was unable to run some items from %systemroot%/system32 that are in my PATH from a command line. All items looked correct in the PATH. Upon further inspection the registry entries for PATH were changed to REG_SZ. When the registry items were changed back to REG_EXPAND_SZ and the system rebooted everything returned to normal. Please check you installer as it is the only thing that could have changed my registry.
curent user (HKEY_CURRENT_USER\Environment)
system (HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Environment)