We always try to leave it better than worse but depening on the type of installation, this can be impossible.

Remember that the installers are contractors and not housekeepers.

We wipe down the windows but they may not be perfect and you ideally shouldn't be messing with them too much from the outset until the sealant cures all the way up.

That's about it. ^... The site should be cleaned with reasonable care, but do understand that the installers are craftsmen, not professional cleaners. The windows and surrounding areas should be picked up, vacuumed, wiped down, etc. We generally cover things up if there is going to be any sawing, drywall dust, etc.

If you have plaster you probally have lead based paint on your windows.The contractor should be following the EPA's RRP rules if the house is pre 1978 or has been tested negtive,this would address alot of the cleaning issues.I typically do RRP containment on windows that are not lead and clean all visable dust on windows and floors.I do not typically clean the glass unless there is sticker residue, and even then I clean just the affected area.

WoW, HomeSealed, & Todd.... thanks for your feedback in this. I was just trying to get some feel on what you guys from the "Top Tier" of contractors suggest.
I've lurked for a few years and have grown to respect your comments/suggestions/recommendations.