It's been while, thank goodness, since I've used Vista. I think there may be unzip software built into the OS. Double click the zipped file and see what happens.
If that doesn't work, try 7-Zip, it's free.
7Zip works fine!
I had accidently set IE as my default unzipper. Let me tell you, do NOT ever do that. It’s not pretty. I had to log off to make it stop flashing black and white.
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BTW
I rebooted with a live disc, PCLinuxOS or something. I am online with no problem. I can imagine all you need is an old laptop without a hard drive, just use the live disc and a memory card and you are A-okay.