Microsoft hung on to Windows 7 RTM for 10 days before signing off on it.

The big news of the week is Windows 7 hitting RTM – but wait, was the release to manufacturing code really finished just this week? No, it wasn't. Windows 7 code was actually wrapped up on July 13, 2009 – 10 days before Microsoft signed off on the RTM.

Microsoft's Larry Osterman shared in his blog the Windows 7 RTM build string: 6.1.7600.16385.

Interestingly enough, the very same build was leaked onto the internet last week. Our first glimpse of build 7600 came with "7600.16384.090710-1945," which was completed July 10, but wasn't the final RTM version.

Just a few days later, another build 7600 leaked, bearing the string "7600.16385.090713-1255," which was completely July 13 at 12:55 p.m. and wears the same numbers as the final RTM.

Of course, it's expected for Microsoft to complete a build of the RTM and hang on to it for last minute testing before signing off on a build that'll be sent out to the rest of the computer ecosystem.

Windows communication manager Brandon LeBlanc explained this in part on the team blog: "What happens is a build gets designated as a RTM contender after going through significant testing and meeting our quality bar for RTM. Then, it goes though all the validation checks required for RTM including having all languages of that build completed. If all the validation checks have passed – sign-off for RTM can occur."

So for those of you who have been hanging out in shadier parts of the internet, that build of Windows 7 that's been floating around the past week claiming to be RTM seems to be solid. Of course, besides the legality of it, downloading any critical software from unofficial sources is risky business.

"As always, beware of what you download. There are many bogus copies of Windows 7 floating around the Internet. More often than not, they contain a rather nice malware payload," LeBlanc added.

Source : Tom's Hardware US