You’re running into
two separate (but related) Windows behaviors:
1)
Drive letters are NOT stored “on the drive” in a portable way.
Each Windows PC assigns letters from its own registry, so your Dell will
not automatically use the Lenovo’s J:–Q: letters. You must set the letters on the Dell too.
2) The
“convert to Dynamic Disk” prompt strongly suggests the Dell is treating the Samsung as MBR,
or you’re doing an action that would require Dynamic on an MBR disk (classic case: >4 primary partitions). A
GPT basic disk should not trigger that for normal partitioning.
Below is the clean way to get this stable.
Step 1 — On the Dell, verify whether the Samsung is actually GPT
- Plug the T7 in.
- Press Win+X → Disk Management.
- In the lower pane, find the physical disk that matches the Samsung T7 size (~1.8 TB).
- Right‑click the left label that says
Disk X (not a partition) → Properties → Volumes tab.
- Check Partition style:
- GUID Partition Table (GPT) = good.
- Master Boot Record (MBR) = that’s why you’re getting the Dynamic prompt.
If it says GPT
Skip to
Step 2 (this becomes “just reassign drive letters and fix the one volume”).
If it says MBR
Then you cannot have all those partitions as a
Basic disk without hitting the 4‑partition limit, and Windows will offer
Dynamic as a workaround (not recommended for portable SSDs).
Best practice fix (destructive):
- Copy any needed data off the Samsung first (if any).
- In Disk Management: delete all volumes on the Samsung → right‑click
Disk X → Convert to GPT Disk → recreate partitions.
There isn’t a safe built‑in Windows tool to convert an external data disk from MBR→GPT in place without risk. Any 3rd‑party “non‑destructive” conversion should be treated as “backup first, then try.”
Step 2 — Make the Dell use the same drive letters (J:–Q
Even with GPT, you must do this manually on the Dell:
- Disk Management → for each partition on the Samsung:
- Right‑click the partition → Change Drive Letter and Paths…
- Change → pick the letter you want (J, K, L…Q).
If Dell won’t let you use J–Q
That means those letters are already taken on the Dell (often by mapped network drives, card readers, etc.).
Check quickly:
- File Explorer → This PC → see if anything already uses J:–Q:
- Or in an elevated Command Prompt:
net use (shows mapped network drives)
Free them (disconnect mapping) or just choose a different unused block (e.g.,
R:–Z:).
Step 3 — “Drive not recognized” on Q:
That depends on the
exact message (Windows vs File History vs another backup tool), but here are the most common fixes:
- In Disk Management, confirm Q: is:
- Healthy
- Has a drive letter
- File system NTFS (File History and many backup tools insist on NTFS)
- Run a file system check (Dell, elevated CMD):
chkdsk Q: /f
- If the error is from File History specifically, tell me the exact wording. File History can be picky about:
- NTFS requirement
- removable vs fixed classification
- certain partition layouts
One thing I need from you to make this precise
Please paste the output from
PowerShell (Admin) on the Dell:
Code:
Get-Disk | Format-Table Number,FriendlyName,BusType,PartitionStyle,Size,IsRemovable -Auto
Get-Volume | Format-Table DriveLetter,FileSystem,HealthStatus,Size -Auto
And tell me:
- Does the Samsung show as GPT or MBR in that output?
- What is the exact “drive not recognized” message you get on Q: (word-for-word)?
With that, I can tell you
exactly whether you need to re-convert to GPT (wipe/recreate) or whether you just need letter reassignment + a quick NTFS/chkdsk fix.