How to add assemblies in a 64-bit machine

My old cmd-script:

C:\Windows\Microsoft.NET\Framework\v2.0.50727\RegAsm blabla.dll
C:\Windows\Microsoft.NET\Framework\v2.0.50727\GacUtil -i blabla.dll

(Which works fine in my old machine.)

But now I have a script for a 64-bit machine (Windows Server 2008 R2):

C:\Windows\Microsoft.NET\Framework64\v2.0.50727\RegAsm blabla.dll
C:\Program Files\Microsoft SDKs\Windows\v7.1\Bin\NETFX 4.0 Tools\GacUtil -i blabla.dll

Then I get this message:

C:\Windows\Microsoft.NET\Framework64\v2.0.50727\RegAsm blabla.dll

Microsoft (R) .NET Framework Assembly Registration Utility
2.0.50727.5420 Copyright (C) Microsoft Corporation 1998-2004. All rights reserved.

Types registered successfully

C:\Program Files\Microsoft SDKs\Windows\v7 .1\Bin\NETFX 4.0 Tools\GacUtil -i blabla.dll 

'C:\Program' is not recognized as an
internal or external command, operable program or batch file.

The second command is not successful.