Fix ERROR_NETWORK_BUSY (0X00000036) on Windows

I know this error is infuriating — you're just trying to open a file or print to a shared printer, and Windows throws up "The network is busy" and stops you cold. Let's fix it now.

Quick fix: Clear the stuck SMB session

This almost always works. Open a Command Prompt as Administrator (right-click Start, choose Terminal (Admin) or Command Prompt (Admin)). Then run:

net session | find /i "\\"

That lists active network sessions from other computers. You'll see something like:

\\192.168.1.50   User01   Administrator 00:03:22

Find the session that's causing the hang — usually it's the one from the machine you're trying to access the file on. To kill it:

net session \\192.168.1.50 /delete

Replace the IP with your actual one. Hit Enter, say Y when prompted. Now try your file or printer again. Nine times out of ten, it just works after that.

Why this works

The error 0X00000036 happens when an SMB (Server Message Block) session gets stuck in a "busy" state. This typically happens when:

A user on another machine opened a file over the network and closed the app, but Windows didn't fully release the file handle.
The remote machine went to sleep or lost network connection while an app had the file open.
An antivirus scan or backup tool locked the file temporarily, then the lock lingered.

By deleting the session, you force Windows to drop all open handles on that connection and renegotiate a fresh one. It's like yanking the network cable and plugging it back in — but without the physical unplugging.

Less common variations of the same problem

1. The printer spooler is holding a lock

If the error happens when printing to a shared printer, the spooler on the host computer might be stuck. On the host machine (the one the printer is plugged into), restart the Print Spooler service:

net stop spooler && net start spooler

This clears print jobs that are stuck with a "printing" status but never finish. After that, cancel any hung jobs from the print queue, then try printing from the remote machine again.

2. The file is actually open on the server

Sometimes the session isn't the problem — the file itself is legitimately open by another user. On the host computer, open Computer Management (right-click Start > Computer Management), go to System Tools > Shared Folders > Open Files. Right-click the locked file and choose "Close Open File". This is the nuclear option, so warn the other user first if you can.

3. Corrupt SMB cache on your machine

If you keep seeing the error even after clearing sessions, your local SMB cache might be corrupted. Run these commands in an admin prompt:

net use * /delete
ipconfig /flushdns
nbtstat -R
nbtstat -RR

This clears all network drive mappings, flushes DNS, and resets NetBIOS name cache. You'll need to remap any network drives, but it's a small price for a clean slate.

Prevention tips

Don't leave files open — close documents and spreadsheets when you step away. That's the #1 cause.
Keep machines awake — set power plans on shared PCs to never sleep. A sleeping machine can leave orphaned sessions that trigger the error.
Update SMB protocol — if you're still on SMB1 (really old), upgrade to SMB2 or SMB3. Windows 10 and 11 default to SMB3, but if you've got legacy gear, check. Run Get-SmbServerConfiguration | Select EnableSMB1Protocol in PowerShell. If it's True, it's time to disable it — SMB1 is a security risk anyway.
Use a short timeout — not a default setting, but you can configure SMB session idle timeout via Group Policy. If this is a recurring problem in an office, talk to your IT admin about setting a 15-minute idle timeout.

That's it. You've got the fix, you know why it works, and you've got options for the edge cases. You won't see this error again — or if you do, you know exactly what to do.