Replacement weatherstripping for "Certainteed" windows

We have 10 "Certainteed" windows of varying sizes which need to have the weatherstripping replaced. The windows were installed in 1996 and both the white fuzzy fibers and skinny plastic core which them have deteriorated badly over time.
The fuzzy stripping is located on the lower window which can be released and dropped down from the frame for cleaning from inside the house. There is a very narrow channel on all 4 sides of the frame where the white fuzzy stripping slides into the parts of the frame which make contact with the upper window for a good seal.