Jailbreaking programs for iPod touch fourth generation 4.2.1?

I can't use greenpois0n because I can't extract winzip files, redsn0w won't download on my computer for some reason, I downloaded limera1n, but it won't work for me (I've tried to jailbreak with it at least 15 times, to no avail), and I don't know if blackra1n will work because it doesn't say it supports 4.2.1. I also don't really want to wait for jailbreakme.com to be running again, but I will if it's my only option.