I believe you place the file in the C:Windows\SysWOW64 directory, then alter the registration command to reflect that specific path. Once the library link is in the WOW64 folder, hit "Start" then hit "Run", then type in "cmd". In the window that pops up, type in C:\Windows\SysWOW64\regsvr32.exe msstdfmt.dll
I could be wrong....never done it on Vista64, but that would seem the logical choice.
Btw....all this is assuming your Vista OS is installed on the "C" drive.......if you're dual-booting or altered the default OS install path, that may not be the case.
Cheers,
Parky