The recommended method to convert these disks is to upgrade the operating system to Windows 10 first, then perform the MBR to GPT conversion. So 2k8 sounds like a no no even for an offline conversion.

This disk management software can convert MBR to GPT without losing any data. Check the table to learn how EaseUS Partition master makes MBR to GPT conversion safe and worry-free: ...

I have a 2TB MBR drive w/ W7 in the 1st partition. Partitions 2 & 3 are used as separate storage. I want to xfer all of that to a 4TB GPT drive including resizing the 2nd & 3rd partitions. Most of ...

Then, right-click the MBR disk you want to change to a GPT disk and select Convert to GPT Disk. What is the number of partitions that the MBR partitioning system can support?

This disk management software can convert MBR to GPT without losing any data. Check the table to learn how EaseUS Partition master makes MBR to GPT conversion safe and worry-free: ...

This disk management software can convert MBR to GPT without losing any data. Check the table to learn how EaseUS Partition master makes MBR to GPT conversion safe and worry-free: ...