Answers

It depends on the type of window.  Is it just a glass replacement or does really need the entire sash?  Sometimes, the I.G. unit can be replaced using the same frame.

Who is the contractor and what did thet do?

Go to Everlastsiding.com

The is no one best gutter protection product.  There are tons of hoods and systems available and everybody claims to have "the best".  I would suggest that you research and make an educated decision.  GutterShutter is a the system that I use.  It is a custom seamless gutter application with a hood that is made in 10' sections and attaches directly to the fascia board on your home.  The big advantage of the hood (though being part of the system) being installed separately is that it allows for maintenance if and when needed.

I strongly recommend staying away from ANY product the has to go under or over any course of shingles on your home.  This is a seal that you do not want to break.

Ask your friends about their personal experiences as a starting point.  I am sure you will both good and bad stories.  You want to make sure that you ask as many questions as possible upfront to reduce surprises during the process.  Take your time, this process should not be rushed.  Make sure the builder know that you want to stay on budget.  Get a list of allowance items and shop the stores to make sure the allowances fit your home.

Most important to me would be to ask the builder for references and go talk to previous clients.

Good luck!

Emails (for documentation) and photos.

Abe has given you a great answer.

Make sure that your attic is properly insulated.  Make sure the seals around all windows and doors are in good shape.  If you can see daylight air is entering and leaving as well.

What year was the house built?  How old are the doors?

Are you looking solely for paint options or new exterior cladding options.  If the latter, go to everlastsiding.com.

Great product.

Is this a skylight or window application?  Do you have any photos to share?

Photos would be needed to give acurate solutions.

Sorry.

Definitely looks like a seal failure.  The seal is broken which is causing the cloudy glass.  If the glass is not under warranty you should be able to contact a local glass company to do the repair for you or you can choose a full window replacement as well.

Good luck.

You should contact Thompson Creek directly to make sure nothing you do will void your warranty.