Hello, I am trying to backup a Windows Server 2008 r2 VM running on ESXi 5.0.0. When I run the Windows Server Backup snap-in it returns the '2155348129' error code. Looking around this seems to be caused byt the OS partition not being active, however since it is a VM I'm afraid changing the active partition will cause it not to boot correctly. The active partition at the moment is a 100MB "system reserved" partition, which i believe contains ESXi "stuff". Any ideas on how to fix it and make a backup of the machine? It seems weird that MS didn't consider virtualized windows machines when they wrote the backup snap-in. Or did I get something wrong? I'd be grateful for any help.