Hello Agent86. Welcome to the forum.
There is some confusion in your explanation of your problem:
- You say: "The original secondary drive (XP) is working and I can store files there"
- And then: "I can't see or read files that were on there before switching to 7. Properties show 160G is used, but no files."
Does this mean that you can write new files to OLD-DRIVE but you can't read them?
Or that you can write and read new files but can't find any of the old files.
What would be really helpful is if you could post a screenshot of your Disk Management and Windows Explorer windows with this OLD-DRIVE connected.