On February 22, Microsoft has released Service Pack 1 for Windows 7. This update includes previously released security, performance, and stability updates for Windows 7. SP1 also includes new improvements to features and services in Windows 7, such as improved reliability when connecting to HDMI audio devices, printing using the XPS Viewer, and restoring previous folders in Windows Explorer after restarting.
I have updated one Windows 7 Home Professional laptop and one Windows 7 Starter netbook. Both installations went without problems, and after downloading the SP1, the installation process took about 15 minutes on both machines. After restarting, both machines booted up and Windows was ready to go.
One thing that I have noticed on both installations of SP1 is that it removes the wallpaper for some reason (probably related to Active Desktop Update contained in SP1). If you need to change wallpaper in Windows 7 Starter, read this article.
Go to download page for Windows 7 Service Pack 1.