Scripting

We're using Offline USMT to upgrade our Windows XP computers to Windows 7. The Windows 7 x86 migration is working great with USMT, however, we receive this error when attempting to run Windows 7 x64 scripted installs. What i mean by this is, we are able to pxe boot into the KBE, select Scripted Install, select the specific migration install that we want to use, it then scans the user states and allows me to select which users i want to migrate across. Once I've selected the users for scan and deploy i select start, which then pops up the command prompt as usual but instead of uploading the user state to our kace server it errors with "Scanstate is not recognized as an internal or external command. The system was unable to find the specified registry key". 

This is happening on all of our 64bit installs, which makes me think that it's not linked to a particular machine but the install itself. We've setup our scripted installs as having the default pre-install task "Scan User States Offline" then mid-level task "Deploy User States Offline" - like i said, works fine with 32bit but not 64bit.

I've noticed that when i look at the Library--> Preinstallation Tasks-->Scan User States Offline and download the .bat file that it calls, it states this:

REM scan user states offline

%windir%\system32\mshta.exe Y:\hta\scan_user_states_offline.hta %1

What I don't understand is that on 64-bit machines, the mshta.exe is located under %windir%\SysWOW64. Could this be a problem? I'm a little confused. Anyway, i created another one of these for x64, tested it and it still fails with the same message.

Does anyone have any ideas regarding this?