Windows 7 is NT 6.1 -- in other words, Vista with fixes.
There was a REAL Windows 7 (NT 7.0) project at Microsoft (a truly new operating system), started a few years ago. Before MSFT admitted that Vista was a failure in the marketplace, the intention was to bring out NT 7.0 around 2010-11. It was talked about but not specified too closely.
When Vista was rejected in the marketplace, MSFT had to bring out -something- immediately to replace it. And it had to have a name that was NOT associated with "Vista".
But REAL Windows 7.0 -- NT 7.0 -- wasn't nearly ready yet.
So they rev'ed Vista from NT 6.0 to NT 6.1, and stole the name of the next planned major release ("Windows 7"), to try to fool everybody into thinking it was really different from Vista.
Now, truth is, I rather like Win7. Been using it for months. I'm not knocking it one bit. But it's not a "new" operating system. It's Vista, the way it should have been two years ago.
I just wonder what the heck MSFT will do for the next major release name. It's going to be NT 7.0, but called.... "Windows 8" ???? This could get silly...