Fix WSAEDQUOT 0X00002755: Quota Exhausted on Windows

This error means a socket call failed because the disk quota on a Windows system is full. It's not a disk space issue — it's a quota per user or per process hitting its limit.

Quick Answer

Run fsutil quota query C: to check per-user quotas. If a user's quota is full, either increase it with fsutil quota modify or disable quotas on the volume. The error isn't about free disk space — it's about Windows hitting a limit on how much quota a user can consume for socket data structures.

What This Error Actually Means

I've seen WSAEDQUOT (0x00002755) pop up in two real-world scenarios: custom networked apps that hammer sockets without cleanup, or Windows Servers running heavy file-sharing workloads like IIS or SQL Server. The OS tracks disk quota usage per user — even for internal buffers and temporary socket files. When that quota hits 100%, any new socket call returns this error.

Don't waste time checking free disk space. That's a different error. The culprit is almost always a user or process that's consumed their entire allotted quota on the volume where %TEMP% or socket buffers live. On a typical Windows Server, that's usually the C: drive.

Fix Steps

Identify which volume has quotas.
Open Command Prompt as Admin: fsutil quota query C: Replace C: with your system drive or the drive where socket temp files live. If you see Quota enabled: Yes, move to step 2.
Check the problematic user's quota.
Same command gives you per-user table. Look for the user account running the failing app (often NETWORK SERVICE, LOCAL SYSTEM, or a specific service account). Note their Limit and Used columns. If Used hits Limit, that's your smoking gun.
Increase the quota for that user.
Sure, you can use the GUI — go to drive properties, Quota tab, Quota Entries — but I prefer the command line for speed: fsutil quota modify C: 1073741824 2147483648 \. That sets a 1GB warning and 2GB limit. Adjust numbers to your needs (values in bytes).
Or disable quotas entirely (if you don't need them).
Open an Admin prompt: fsutil quota disable C:. Reboot the affected service or app. Quotas are often left on by default in Windows Server SKUs and nobody remembers they're there.
Restart the failing service.
After raising quota, restart the service or process throwing the error. If it's a custom app, kill and relaunch it.

Alternative Fixes If the Main One Fails

Check per-process quotas — some apps like SQL Server have their own internal quota limits. Look in the app's config or registry under HKLM\SOFTWARE\Microsoft\ for a Quota setting.
Clear %TEMP% — socket operations sometimes write to temporary files. Run del /q /f %TEMP%\*.* (close apps first). That frees up quota used by old temp files.
Run as a different user — if the app runs under a service account with a tiny quota, switch to LOCAL SYSTEM or create a new account with higher quota.
Check for disk quota per process — use wmic process where name="yourapp.exe" get ProcessId,QuotaUsage (may require admin rights). Some versions of Windows report quota usage per process.

Prevention Tips

Monitor quota usage — set up a scheduled task that runs fsutil quota query C: weekly and logs it to a file. Anything over 80% triggers an alert.
Set realistic limits — for service accounts running web servers or databases, set quota limits 4-8 GB instead of the default 1 GB. The default is too small for any real workload.
Disable quotas on volumes that don't need them — if you don't actively enforce disk quotas for users, just turn them off. It's one less obscure error to debug.
Log the exact user hitting the limit — add %windir%\system32\logfiles\quota\quota.log to your monitoring. The log contains user SID and timestamp. Much faster than guessing.

I've seen this error kill a production IIS server for an hour while three admins checked disk space and rebooted the server twice. The fix was fsutil quota modify. Don't be that team.