when I plug it in on windows 7 it says its missing a component, I am a beginner on this so I know what to ask
Its not what you need to ask rather what you need to mention.
WHAT is saying it’s missing a component, Windows 7 or the Flash drive?
WHAT component is missing?
WHAT version of the SanDisk Flash drive do you have? ie does it have Backup Software on it or U3?
Do you have the same problem on different computers?