squeeling noise

[s,one]

I get a high pitch squeeling noise just after start up with my car which goes after a few seconds running ,but all the same I like to stop it. I have checked the front belt which seems tight so am I likely to cause any damage if I tighten it. Or am I looking in completely the wrong place.
Excuse my ignorance but is the belt that is set further back running the alternator or the power steering and is it possibly this causing the noise, and is there any adjustment.

Cheers

Steve