→ Applies to: Hyperion 9.x and above

The Hyperion conversion process includes a post-conversion driver installation service that runs inside the Windows guest. In some cases, this service fails to complete successfully, causing the guest to restart continuously instead of finishing setup.

Symptom

After converting a Windows VM in Hyperion, the VM enters an endless restart loop — the guest boots, then restarts again shortly after, repeating indefinitely. This is a normal restart loop, not a BSOD (Blue Screen of Death).

Solution

Step 1. Start the Windows VM in Safe Mode

NOTE
Interrupt the restart loop by forcing Safe Mode — for example, by holding Shift while restarting from the Windows recovery options, or by pressing F8 repeatedly during boot, depending on the Windows version.

Step 2. Open the Run Dialog box, then open the System Configuration utility menu

Windows key + R

msconfig

Step 3. Locate the driver installation service “Virt tools firstboot service” from the services tab

Step 4. Disable the service by unchecking the box next to it, then click on Apply and OK

Step 5. Reboot in Normal Mode