What is the PG on the window? Impact window are NOT cheap and while they will help with the noise and certainly with storm protection, might be a handful of "tightening" measures you can do to help with the noise before taking a big expense leap forward.

@Windows on Washington Ltd please explain how the OP is to tell you the PG of their windows when they wrote: "I wanted to understand the specs of the current windows before I start calling around for selected replacement windows in hopes of not having to replace ALL the windows due to style/quality differences. For the life of me I can't seem to find any identifying marks on the existing windows."

@Eric H - even if you knew the specs of the windows when they were new, I don't think those old specs would give you any kind of useful benchmark to buy windows today. Millions of people move into houses and replace the windows when they have no idea what brand the existing older windows were or their specs.

I would replace in a first stage just the windows in the room or rooms that are the most problematic in the way of the traffic noise and/or where you feel they may be weakest or most deteriorated. After that, take stock of whether you want to continue in other rooms.

I understand you are concerned about contractors wanting to upsell you. But at some point - even if you knew the specs of your existing windows - you are going to have to rely on a windows contractor. If you have 3 different quotes to do just 1-2 rooms, you can get a feel for the cost, and for those contractors' reliability. It would also help you a lot to go to windows showrooms and ask questions and look at what is available. Manufacturer websites will tell you where those showrooms are, as well as provide a list of approved installers.

@M Miller

Good question. Perhaps the OP has browsed around a bit more at this point and located some threads where folks have informed @Eric H how to locate the serial number or some sort of identifying marks.

The windows are 10 years old, not 30. I haven't been into a home with 10 year old windows and NOT been able to deduce who the manufacturer was.

I would start with the normal locations such as:

1. Side rails of sashes on the pictured single hungs
2. Look for other operators in the home and look where the window shuts into the pockets
3. Pull the balance channel covers and peek inside there
4. Etchings in the glass
5. Historical build/HOA documents

That would just be a few of the places to start.

@Windows on Washington Ltd ... I agree that its surprising that I have yet to find any markings. I previously looked at ALL the windows for labels at the side rails and top and bottom pockets or etchings on the IGU glass or spacers and haven't found anything. There are some plastic covers hiding the balance mechanism and I pried them off on several windows hoping to find a hidden label -- with no luck. The HOA that I am in had several different builders and the original contract that I found just mentioned low-e vinyl single-hung windows so no luck there. The reason I posted the pictures was that I hoped someone with more experience might recognize the specific hardware or latching mechanisms that might be traceable to a particular Mfg.

I guess I was hoping that any replacement windows that I get might better match the style/look of the existing ones... but that might not be possible if these existing windows are truly "no-name". I'm thinking that they MIGHT be PGT or MI-Windows but that is just because those seem to be popular brands in this area.

I figured I would dig deeper on the windows in the garage since I'm less likely to do real damage. I pulled the entire moveable sash the other day and looked over all the edges and where it met the fixed sash - still no luck. I didn't really see a way to pull the fixed sash without doing damage so I stopped there.

Ask neighbors or if there is a forum for the neighborhood. Your efforts might be fruitless at the end, but someone knows and can ID it even by look.