answer:I wouldn’t say extending the life of the computer is really possible through the use of an external hard drive. But in terms of performance what I do is as follows. Store all of my data, for pretty much everything, documents, music, movies, profiles, anything on my external while backing up everything to an online service. Every six months I reformat and reinstall all my programs without worry of losing data because it is all saved on my hard drive. This would solve your issue of you computers slowing down, but not necessarily extend the life of it. The major advantages of external hard drives is data storage and security rather then performance. This also depends on how comfortable you are with starting from scratch and making sure you do not lose anything important. Overall i don’t see much performance gain possible with just an external drive.