“When using system Center Virtual Machine Manager 2008 (SCVMM), a P2V conversion of Windows Server 2003 R2 may fail with Error 13257 trying to patch the source prior to the conversion. This error actually occurs on the “Conversion Information” dialog during the P2V wizard before actually starting the conversion. The following errors occur during the P2V conversion using SCVMM: Error (13257) (see pic),” explains Microsoft in KB2131553. To resolve: Check to see if vmmservice.exe and vmmservice.config files are located in same folder. If so, remove or rename the vmmservice.config file and then try conversion again. After removing or renaming vmmservice.config file the conversion should complete normally.