Many applications and browsers (like legacy versions of Chrome or Firefox) require SP1 as a baseline.

After installing SP1, Windows 7 Starter may feel sluggish as it re-indexes files. Give it an hour of idle time to finish background tasks. Is Windows 7 Starter Still Safe to Use?

Click the Start button, right-click Computer , and select Properties . If it says "Service Pack 1" under the Windows edition, you already have it.