According to Rafael at the Within Windows blog Microsoft may preparing to test Windows 7 SP1 with external testers. Similar to Windows Vista service pack beta tests, a special registry key is set on computers eligible to receive the beta service pack via Windows Update. While the registry key has been identified the value (secret download ID) is unknown.
Windows 7 SP1 Beta Coming Soon
Published in Windows 7 News by Steve Sinchak with 7,424 views
