Try playing the tape in an additional audio or video player. Sometimes it is the tape deck or VCR that is damaging the tape. If your tape plays identically in both players, move on to step 2.
Rewind the tape all the way to the beginning, fast-forward it all the way to the end, and rewind to the beginning again. Sometimes a section of the magnetic tape will be stuck or wound incorrectly. Rewinding the tape around each spool can bring the tape back to working condition again.
If you have an audio tape problem, bake your tape in the oven. Although this is not always recommended as a permanent fix for the tape, it can be repeated multiple times and in most cases helps the tape to temporarily sound better. Preheat a conventional oven to 130 degrees and place the tape inside for two hours. Remove and let the tape cool before trying to play it again.
If you still cannot play your tape, purchase a video and audio repair kit from your local drugstore or electronics store. If you can determine the spot where your tape is dragging, stop the tape at that point and very carefully splice and re-tape the magnetic tape back together. Although you may lose a few seconds of your tape's material, you can save your tape for good.
Back up your tape. Now that you know tapes don't last forever, back up your tape while you have the chance. Make another tape as backup and back up the material to CD and as a computer file as soon as possible.