Earlier this month, as the Windows Update launch date for the service pack.

" Starting today, Windows 7 Service Pack 1 will be available to everyone via the Microsoft Download Center and start rolling out via Windows Update," said Microsoft spokesman Brandon LeBlanc in a Tuesday post to the .

When delivered via Windows Update, Windows 7 SP1 weighs in at approximately 750MB for the 32-bit version, just over 1GB for the 64-bit edition.

A much larger version is available on for users needing to upgrade multiple machines.

Customers in the U.S. and Canada can also order a Windows 7 SP1 installation DVD from Microsoft; the DVD is free, but shipping runs $5.99.