Finally the cat is out of the bag with leak of first ever Microsoft Windows 7 Service Pack 1 screenshots, the series of images posted at a non-english blog shows the SP1 installer suggesting that it sizes around 149.4 MB in its current build form.

According to the blogger the total number of updates in the current build of Service Pack 1 is around 150, these updates bring the Windows 7 compilation build number between: 7600.20500 and 20,700.

We have posted about indicative proofs of Microsoft doing internal Windows 7 SP1 testing and now to further support the unconfirmed news bloggers at ZDNet are now reporting that they have received several reports supporting claims of undergoing Windows 7 SP1 testing and have seen lists of post-RTM build numbers for Windows 7.