Windows 7: What do I have???

I've received an email from MS about downloading Windows 7 RTM that will expire June 01, 2010. The file name seems to indicate that it is version 7100:

7100.0.090421-1700_x64fre_client_en-us_retail_ultimate-grc1culxfrer_en_dvd



The current Windows 7 version I have is:

Windows 7 Evaluation copy. Build 7100

This is what the version command puts out, confirming the above:

C:>ver
Microsoft Windows [Version 6.1.7100]

Do I already have the RTM version, or what is the version I have? It did not stop working on July 1st and it still runs just fine.
TIA...

Cr00zng

You have the public release candidate. It will expire next year.

Thanks Azural....

I actually installed my Windows 7 sometimes in January. Interestingly, at work I've also installed it on PC and that did expire on July 1st.

Why is my built version is different from yours? Not to mention that I've seen in this forum people talking about build version 7600. Why is there difference in the build versions?
TIA...

Cr00zng

Everyone with a different build than 7000 or 7100 is using a leaked (non-public) build.

7600 is supposedly the final RTM build, but I don't believe it's official yet.

The reason there is difference in the versions is that Windows 7 has been in continuous development with MS creating many different builds aside from the public beta build (7000) and the public release candidate (7100). As was said, many of these builds have leaked and are available for download from unofficial sources. Many people here are running such leaked builds.