If the computer still does what you want it to do, then just store the files to CD, which BTW you should have been doing from day one, as if your hard disc failed you would loose everything.
Make sure you store the CDs upright and in there Jewel Cases, as contrary to what the manufactures would have you believe, they are not indestructible and also only have a life span of about 30 years. Another point is only use a CD Marker Pen if you wish to write on them, as the label side is the most fragile part of the disc. (Even a scratch will cause you to loose data, and you can’t polish the label to fix it)
Hope this helps.

Bill