Hello jpaulus
Your Windows installation was damaged somehow so you should run Windows Vista recovery tool to repair it. To do this, please follow these steps:
1. Insert the installation disc.
Note: In Configuration Editor change boot sequence to CD-ROM,Hard Disk,Floppy.
If you installed Vista from image file go CD/DVD-ROM Options and select "Use image file"
Than enter the path to your image file in line brlow.
2. Reboot VM
3. Set your language preference, and then click Next.
Note In most cases, the startup repair process starts automatically, and you do not have the option to select it in the System Recovery Options menu.
4. Click Repair your computer.
5. In the System Recovery Options dialog box, click the operating system that you want to repair, and then click Next.
6. In the System Recovery Options menu, click Startup Repair to start the repair process.
7. When the repair process is complete, click Finish.