Balance spring replacement?

Swisco,
i'm not sure if I need to replace my balance springs or not. My windows were put in June, 2005. They are extremely hard to open and close throughout the entire house. It's hard to believe that all balance springs went bad, or if they were simply installed incorrectly. What do you think?
Thanks a ton!
Jason

Thanks for responding so quickly, Dave. That's a good point you raise about the pivot shoes. I took out my balance springs and just used the pivot shoes. It has the same level of resistance and there doesn't seem to be any difference in the upward/doward motion (with window sash in place).
When I pull up and down on the pivot shoes (w/o window sash), they have some resistance, and don't seem to be moving freely.
What do you think?
Thank you!
Jason

I finally took some photos of my window balances. Please let me know if you need more to help find the solution to my problem. I'll remind you of what I got going on.

My wife and I have been living in our condo for approximately 6 years now (new construction). All of our windows are EXTREMELY hard to open and close. We have vinyl, double hung windows. I went over most of the possibilties, and need help narrowing it down. I believe that the windows are square. I took out the balances and the window opens/shuts fairly smoothly (obviously heavy), but does not seem to have any obstructions. I recently bought two new swival balances from a window store (to see if it solved the problem), but paid way over market value.

The windows are still somewhat hard to open and close. I don't know if adjusted them correctly. Youtube says that I should install the swival balances and turn them 10-12 times and then connect them to the shoes. Again, this seemed to make it a little easier but I still feel that they could open/shut a lot better and smoother. Please find the attached photos.
Thank you for your time.
Kindly,
Jason

Hello Paul,
I finally weighed my windows. They are approximately 25 lbs. The window diameter is 34" wide and 30 1/2" long (vertical). The swivel balances are about 29 1/2" long. I am wondering if the balances are too small for my windows. What do you think?
Thank you,
Jason

Hi Paul,
Thanks responding so quickly. Currently, I have the yellow-tipped balances. I purchased a orange tipped balance from my local window store, but it didn't seem to do the trick. You suggested the blue-tipped balances for the weight of my window sash. Do the different colors signify different weight classes? Maybe I should have bought blue-tipped balance from my local window store (for my window sash that weighs 25 lbs.). What do you think?
Thank you,
Jason

Paul and Donna,
I wanted to give you an update on my window balances. I purchased all new balances (blue-tipped, S600-30, taking your suggestion). I watched your youtube video on charging the balances. I was overtightening them before, and with the new balances I purchased from your store, they seem BRAND NEW!! It's amazing what new balances can do. I recently moved into a different home and now have the same problem with my windows. Some balances are good and some are bad. I will purchase new balances throughout the entire house to hopefully get the same result...NEW WINDOW FEEL! Thank you for all your patients and help with my problem!!