My Mac Book Pro was going away for maintenance. So I backed up the virtual machine to two separate external hard drives. After I got the computer back, I reinstalled Parallels and copied the virtual machine back to the computer and fired up Parallels. It started ok but on next boot the Windows went into automatic disk repair because it found something wrong with the disks. The automatic disk repair did repair the disk. However, after launching windows and logging in after few seconds the virtual machine crashes with the blue screen. I tried the same with the another copy of the backed up virtual machine - but with that too it is the same. I am using MacBook Pro running OSX Yosemite 10.10.3 running Parallels 9 for Mac build 9.0.24251 and the guest OS is Windows 7 Ultimate 64bit. Any idea what could be going wrong here and how to fix this?