If you're running 64 bit windows then the 64bit version. The difference is to do with the winzip executable and nothing to do with the types of files your decompressing, that's irrelevant, its just a stream of numbers to winzip. It will unzip files to their original state, whether they are intended to be 64 bit or 32bit is nothing to do with winzip.
Erm I meant winrar obviously :-)
Edited by mj2c (02/03/13 09:20 AM)