If you're not sure about whether to let Microsoft install particular updates - don't. As long as you have updates enabled (from the Windows Security Center), anything important will install itself automatically. Anything that Windows asks you if you want, you probably don't need it, and in some cases may be better off without it (for example, "Windows Notification Advantage" or something like that - I forget the precise words - which would, if installed, use processing power to prowl around your system trying to sniff out evidence of you using a pirated version of Windows.)