Have a look on a few windows 7 websites and I guess Microsoft. There you will find the checksum for RC1. This will tell you, if it matches the RC1 download you have, that your copy hasn't been hacked or corrupted. If it's different, avoid.
It will look something like this:
SHA1: 6071184282B2156FF61CDC5260545C078CCA31EEISO/CRC: ABA5A48
Anyway, hold the front page: build 7127 is all over the internet if you feel lucky!
