When downloading leaked builds, always check the hashes to ensure that you have an image that has not been tampered with. Recently, attackers pushed out fake copies of Windows 7 RC on Bittorrent to build their botnet.
You can check the MD5 hash of an image by using MD5Checker (download here). The hashes are as follows:
Windows 7 Build 7127 x86 (32-bit):
7127.0.090507-1820_x86fre_client_en-us_Retail_Ultimate-GRMCULFRER_EN_DVD.iso
MD5 4045CB2A8E50B65ED9E1C2B8D6026B2F
SHA1 F2D615E674B64053D299CFA5E80B777269F0DFF2
CRC-32 F691687F
Windows 7 Build 7127 x64 (64-bit):
7127.0.090507-1820_x64fre_client_en-us_Retail_Ultimate-GRMCULXFRER_EN_DVD.iso
MD5 F805A6595DDC6D12956588BB0F1B9B83
SHA1 9BEB69BE3C2D113ECEB944145951A2123FBBBBF8
CRC-32 460FAD4E
Download:
Windows 7 Build 7127 32-bit
Windows 7 Build 7127 32-bit
Windows 7 Build 7127 64-bit
Windows 7 Build 7127 64-bit