Recently ran across a situation where a Windows XP vDisk streamed from a 5.1 Provisioning Server stated that “NTLDR is Missing”. According to all parties, there were no errors during the creation of the image from the creation of the vDisk on the PVS, to the OS load, all the way through the XenConvert process to convert the VM to a vDisk. After XenConvert completed successfully and attempting to boot from the vDisk, you would see the following:

The Windows XP VM was built using the XenServer Windows XP SP3 template. I’m not exactly sure how it happened, but the C: drive was formatted using the FAT32 file system. The vDisk was formatted on the Provisioning Server using NTFS. Thus, the formatting mismatch lead to the vDisk boot problem.

The Windows XP file system was converted to NTFS and XenConvert was used once again to convert the VM to a vDisk. Once completed, VMs could boot from the vDisk.