I have only .dll file. I have assigned strong name to dll using ilasm command. I want to register it in GAC but i am getting following error:

Dll Name :DDayICal.dll

C:\Program Files (x86)\Microsoft SDKs\Windows\v7.0A\Bin\NETFX 4.0 Tools>gacutil -i "C:\Users\Administrator\Desktop\DDayICal.dll.dll" Microsoft (R) .NET Global Assembly Cache Utility. Version 4.0.30319.1 Copyright (c) Microsoft Corporation. All rights reserved.

Failure adding assembly to the cache: The system cannot find the file specifie d.

  • 2
    It's called DDayICal.dll.dll? Not just DDayICal.dll
    – eirikb
    Oct 20, 2012 at 12:53
  • Sorry Its my mistake. just DDayICal.dll Oct 20, 2012 at 13:02

3 Answers 3


Make sure the dll you downloaded matches your development machine as if both are for x86 processors or if they are for 64 bit, if that's fine then just drag and drop DDayICal.dll to Gac and do a IISReset, and reference it to your project as well, it should work straight away without giving an error for strong file name, however you should check these links out as they got similar type of problem,




EDIT another way of resolving problem you got,


Hope it helped :)

  • Drag and Drop strategy for Dlls into Gac isn't recommended FYI. Oct 20, 2012 at 13:48
  • you should be creating a solution file using wsp builder for your webpart :) Oct 20, 2012 at 13:49
  • I think so You are right..But I have registered dll in Microsoft.net > GAC_MSIL.. But again it gives error "Could not load assembly. The system can not find the File specified." And not working drag and drop strategy for this dll.. It's third party dll. So I have no code. Plz help me.. Its urgent.. Oct 22, 2012 at 4:43

Just execute the next bit running as local administrator.

[System.Reflection.Assembly]::Load("System.EnterpriseServices, Version=, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a")            
$publish = New-Object System.EnterpriseServices.Internal.Publish            

Instead of using drag and drop, use powershell or gacutil.

Powershell example: http://technicaltrix.blogspot.dk/2014/10/install-dll-in-gac-using-powershell.html

GACUtil: https://stackoverflow.com/questions/2182316/how-to-register-a-net-dll-in-gac

  • a server would not have gacutil
    – Pantani
    Jan 6, 2016 at 9:12

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