I have installed a DLL using the gacutil.
gacutil.exe /i SI.ArchiveService.CommonLogic.Exceptions.dll
Using the gacutil /l shows that it is indeed installed.
SI.ArchiveService.CommonLogic.Exceptions, Version=1.0.0.0, Culture=neutral, PublicKeyToken=925c8734ae397609, processorArchitecture=MSIL
Then I wanted to uninstall it.
gacutil.exe /u SI.ArchiveService.CommonLogic.Exceptions.dll
Microsoft (R) .NET Global Assembly Cache Utility. Version 3.5.30729.1
Copyright (c) Microsoft Corporation. All rights reserved.
No assemblies found matching: SI.ArchiveService.CommonLogic.Exceptions.dll
Number of assemblies uninstalled = 0
Number of failures = 0
Why doesn't this work? How do I uninstall it?
Installing an assembly requires the path name of the DLL. Uninstalling requires the display name of the assembly. They don't have to resemble each other. Review the Assembly.FullName property. gacutil.exe /l (ell as in list) gets you a list of display names.
Nevermind.
gacutil.exe /u SI.ArchiveService.CommonLogic.Exceptions
Did the job. Also navigating to C:\WINDOWS\assembly, right-click on it and then choose uninstall would do it. I figured it out by looking at its properties and the name was without the dll extension.
This is a little safer if you have multiple assemblies with the same display name in the GAC
gactutil.exe /u myDll,Version=1.1.0.0,Culture=en,PublicKeyToken=874e23ab874e23ab
Came here while finding answer but did not get fully .
what you actually need to do is to use double quotes "Assemblyname" surrounding complete assembly name i.e
"YOURDLLNAME, Version=6.3.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"
Complete process , navigate to this path using command prompt : C:\Program Files (x86)\Microsoft SDKs\Windows\v8.0A\bin\NETFX 4.0 Tools
and run query : gactuil.exe /u "YOURDLLNAME, Version=6.3.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"
Hope this helps someone
来源：https://stackoverflow.com/questions/5431412/i-can-install-via-gacutil-but-not-uninstall-the-same-dll