Fix 0X00000A4F: Vendor name in use by another record

What's happening here

You're seeing 0X00000A4F with the message "Vendor name is in use by some other vendor record". That's a Windows networking error from the Remote Boot service (NERR_RplVendorNameUnavailable). It means the vendor name you're trying to add—like "Intel" or "Realtek"—is already assigned to another record in the Remote Program Load (RPL) database.

This usually shows up when you're setting up or managing network boot services on an older Windows Server (2003, 2008, or even 2012 with legacy RPL). Maybe you're adding a new network card vendor, or you imported a config file that doubled up a vendor name. The fix is straightforward, but you gotta be careful—messing up the RPL database can break network booting for your clients.

Before you start

You'll need admin rights on the machine. If you're on a Domain Controller, run everything as Domain Admin. I'm assuming you're on Windows Server, but the same error can hit on Windows 10/11 if you've got the RPL service running for old-school network boot.

Fix 1: The 30-second check—RPL Manager GUI

This is the easiest and safest. It works 80% of the time.

1. Open RPL Manager. You'll find it in Administrative Tools or run rplmgr.exe from a command prompt.
2. Click the View menu and select Vendors.
3. Look through the list for the vendor name you're trying to add—say, "Dell" or "IBM".
4. If you see it already there, double-click it, then check if it has any Profiles listed. If the vendor has no profiles, you can delete it safely. Right-click the vendor and choose Delete.
5. If the vendor has profiles, you can't just delete it. You'll need to either rename the existing vendor or use a different name for your new one.
6. After deleting or renaming, try adding your vendor again. It should go through now.

Expected outcome: After you delete the duplicate vendor entry, you should be able to add it fresh without seeing the error. If you're still stuck, move to Fix 2.

Fix 2: The 5-minute registry edit

If the GUI didn't show the duplicate, the vendor name might be buried in the registry. This is where RPL stores its data, and sometimes the Manager doesn't refresh properly.

Warning: Editing the registry wrong can mess up your system. Back it up first. I've seen admins delete the wrong key and kill network boot for days.

1. Press Windows + R, type regedit, and hit Enter.
2. Go to this key:
   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Rpl\RplBoot\Vendors
3. You'll see a list of subkeys—each one is a vendor name in hex format. For example, 0000 might be "Intel", 0001 might be "Realtek", etc.
4. Look at the VendorName string value inside each subkey. Find the one that matches your error—e.g., "3Com".
5. If there are two subkeys with the same VendorName, you've found the problem. Right-click the duplicate subkey and choose Delete. Usually, keep the one with the lower hex number (it's the original).
6. Close Regedit. No need to reboot—RPL Manager picks up changes live.
7. Go back to RPL Manager and try adding the vendor again.

Expected outcome: After removing the duplicate registry key, the error should vanish. If it still doesn't work, you've got a corrupt RPL database—that's Fix 3.

Fix 3: The 15+ minute advanced fix—rebuild the RPL database

This is the nuclear option. Only do this if Fix 1 and Fix 2 didn't work. It wipes the RPL configuration and forces a fresh rebuild from the system's network adapters.

1. Open an elevated command prompt (Run as Administrator).
2. Stop the RPL service:
   net stop rpl
3. Rename the current RPL database folder so you can restore it if needed:
   ren C:\Windows\System32\Rpl Rpl.old
   (Path might vary—check HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Rpl\Parameters\DatabasePath for the exact location.)
4. Start the RPL service again:
   net start rpl
5. The service will create a fresh, empty database. Now you need to re-add your vendor entries. Open RPL Manager.
6. Go to View > Vendors. The list should be empty. Add your vendor name now—it should work without the error.
7. Re-add any profiles, boot blocks, and client records you need. This is the tedious part—you'll have to manually re-enter everything.

Expected outcome: A clean RPL database with no duplicates. The vendor name error should be gone for good.

One more thing—check for read-only RPL files

This is rare but I've seen it. If the RPL directory or its subfolders are marked read-only, the Manager can't save new vendors. Right-click the C:\Windows\System32\Rpl folder, go to Properties > General, and uncheck Read-only. Click Apply, then try again.

That's it. You should be back in business. If not, you might be dealing with a corrupted OS install—try a repair install of Windows or restore from a backup of the RPL database you made in Fix 3.