Q: How to access a mac raid drive on windows?

the drive needs to be in a format that windows sees.

without 3rd party utilities Windows does not read Mac Extended drives and even then depending on how the RAID was built it's no guarantee that Windows will see it as a RAID.

if you need to see the drive itself USING WINDOWS it should be found in

START>Administrative Tools/Disk Management

if not it's likley gone as well.

did you try Administrative Tools/Disk Managment from the Windows control panel?

you will need to partition and reformat it in there to be seen by the system elsewhere.

Does Device Manager show the disks?

Can you feel/hear the disks spinning?