Identifying Which Windows 7 Build I have

Another question about hash files

Are the hash files from regular store bought dvds different than the hash files on the technet site. The reason I'm asking is someone I know has a hash file of:
SHA-1: 2874F721BBFC83C071F4D7F569BAE1A7C38A62E7
and technet's, as listed on the FAQS on this site, say for windows ultimate 86 the hash shoiuld be:
SHA-1: 5395dc4b38f7bdb1e005ff414deedfdb16dbf610

I also have this one as well -
SHA-1: 4fb88ed0e763a0cd82d388e7fdaabd10fc0846d1

can someone explain the difference to me? or if it even matters - I was guessing that the retail get different hashes than technet's depending on date of release due to updates etc. can this be confirmed?

thanks for help