Different types of screeching can come from different things associated with the window.
You could find out if it's just from the squeegy like plastic part on the outside and/or inside by spraying them with soapy water and rolling up and down to see if it goes away. Soapy water will lube it up more than glass cleaner. Both are very short temporary fixes.
It could be from some sandy like dirt, or even a BB in one of the window channels that's scraping/scratching the glass while you roll it up and/or down.
Otherwise there are several parts of the regulator that should/could/would like some lube.