use 7zip its open source and you can find it at its website or i uploaded it here:
http://www.subsim.com/radioroom/down...o=file&id=1362
its what 95% of the modders use, its great and as far as i know it works with all zip files but when its unpacked using winrar zip program it sometimes gets corrupted but i thought that was just when it was winrar but i guess other zip programs have trouble with it too.