Installing Windows With Two Drives Unplug the Second Drive First
Install Windows with the old drive still connected and setup may park the boot files on it. The PC runs fine — until that drive comes out. Thirty seconds of unplugging before install prevents the whole story.
🎥 Watch the video — the missing drive fix and the RST VMD RAID settings shown live
Here is a disaster that has nothing to do with drivers: you install Windows on the new SSD while the old drive is still connected, everything works — until months later you remove the old drive and Windows will not boot at all. Setup quietly placed the boot files on the other disk. The prevention costs thirty seconds before you install: disconnect every drive except the target.
Disk Management — where did the boot files land
Disk 0 (old HDD) ... EFI System Partition <- boot files here
Disk 1 (new SSD) ... Boot, Page File, C:
Windows runs from Disk 1 but STARTS from Disk 0.
Remove Disk 0 and the PC cannot boot.
The two labels that give it away: the EFI System Partition and the C: drive living on different disks. Windows works — until the wrong disk comes out.
1
Why Setup Splits the Boot Files
Windows Setup places the EFI system partition on the first suitable disk it finds — usually the one the BIOS lists as Disk 0 — even when you install Windows itself onto a different drive. If the old disk already carries an EFI partition from a previous install, setup happily reuses it. Everything then works perfectly, which is exactly why the trap goes unnoticed: the dependency only reveals itself when the old disk is removed, formatted, or fails.
2
The Rule — One Drive Connected During Install
Shut the PC down and disconnect the data or power cable of every drive except the one receiving Windows. On a laptop with a second M.2 slot, removing the extra drive is best; disabling it in BIOS works on boards that offer it
Also remove USB hard drives and memory cards — setup counts them when choosing where boot files go
Install Windows normally. With only one disk present, setup has no choice: EFI partition and Windows land together
After Windows boots and updates, shut down and reconnect the other drives
Check the result in Disk Management: the EFI System Partition and your C: drive should sit on the same disk
3
Already Trapped — the Boot Files Are on the Wrong Disk
If your PC already runs in the split state, do not just yank the old drive. You can build an EFI partition on the Windows disk from inside Windows using DiskPart and bcdboot C:\Windows /s Z: /f UEFI after assigning the new partition a letter — a careful job that has no undo for typos. Simpler and safer for most people: back up your files, then reinstall with only the target drive connected, following the rule above. Either way, fix it deliberately, on your schedule — not on the day the old drive dies.
🔴 Honest note: this trap is also why a PC can refuse to boot after you remove a totally unrelated data drive or after the old HDD fails. Before condemning the SSD, ask where the EFI partition lives — the fix may be boot files, not a new Windows.
🎥 Watch the Complete Fix in the Video
The video covers the drive visibility fixes; pair it with this rule before your next clean install on a two-drive machine.
Why did my PC stop booting after I removed the old hard drive
Because Windows was booting from an EFI system partition stored on that old drive, even though Windows itself lives on your SSD. Setup placed the boot files on the first disk it found during installation. The cure is an EFI partition on the Windows disk (created with DiskPart and bcdboot) or a clean reinstall with only the target drive connected.
How can I check whether my boot files are on the wrong disk
Open Disk Management in Windows and look for the partition labelled EFI System Partition. If it sits on a different disk than your C: drive (which is marked Boot), your PC depends on both disks to start. That is the split state — plan a fix before removing or formatting either disk.
Does the one drive rule apply to USB drives and memory cards too
Yes. Setup considers every attached storage device when placing boot files, and a USB drive left plugged in can also confuse drive letters and error 0x80300024 situations. For any clean install, the target disk should be the only storage connected — internal or external — until Windows is fully up.
This guide is based on the Technical Anshu video linked above • Stuck on a step? Ask in the video comments — you will get a reply 🙏