Windows are hard to open

Thanks for posting, Donna. I'm not actually sure what you mean when you reference the stops in this case. What part in particular are you referring to? Can you show me a photo of it?

As for window brand, sometimes it matters, sometimes it doesn't. Most window manufacturers use generic parts. If you're asking if knowing the brand will lead you to the exact part you need, then the answer is probably going to be no. Even if this part is brand-specific, it's always better to go off of its physical design. That's why we always ask for photos.

Thanks! I understand now. What you're showing me here is the top portion of a coil balance assembly. You definitely have the coil springs, I can actually see them peeking out from under the plastic cover.

The function of these balances is basically just to keep the window up when you raise it. If your windows are hard to open it's probably because these springs are getting weaker with age and are more and more unable to actually support the sash weight. It happens all the time. Springs like this can only last so long before finally giving out.

The good news is that we can definitely help get this window working again. However, before I recommend anything, I'd like you to show me a picture of the bottom part of the balance assembly: this part is called a pivot shoe and it should be right under the top portion that you're currently showing in these photos. If I can see a clear picture of the pivot shoe, I can tell you everything else you need to get this window working again.

That is indeed the part I wanted to see, thank you! That pivot shoe there is our 15-199, which is compatible with two different types of coil spring: the 1/2" thick Series 160 and the 3/8" thick Series 165. 

You will need to measure the thickness of the old springs to confirm which one to go with, which unfortunately means you might have to take them out. It's not always easy to get that measurement while they're installed. I do think that if you replace the springs then your window will work just like it did when it was new, since your covers and shoes appear to be in good condition still and they likely don't have to be replaced.

It's ultimately up to you how you want to get the measurement of those springs. I think your best bet is to remove them first, but I understand if that's more work than you had intended before you actually had replacements on-hand. Just understand that you won't get an accurate measurement otherwise.

We do have a video, as a matter of fact. I will share that at the end of this post. Let me just go over your other questions, first.

• No special tool will be needed for this project, you really just need a flat-head screwdriver.
• There is a good chance that the balance configuration is the same between all the windows you've mentioned. However, if the size of the windows vary, then the strength of the coils in each respective window will almost definitely also be different. Strength is indicated by a stamp printed on each spring, which unfortunately means you will have to take them out to gauge which option to pick. If every window is the same exact size then this will not be a concern, you can get away with just checking one.
• We do recommend replacing both sides at the same time, yes. Mixing and matching old and new balances leads to the new balances wearing out faster, since they have to pick up the slack for their weaker partner. 

I hope this information helps. Here is the video I mentioned:

Knowing the serial number of each window will not tell us what the balances are, unfortunately. If you suspect that they're all different then you will have to take them on one at a time. 

As for delivery time, we offer a bunch of different shipping options so it will depend on what you pick before you finalize the order.