Depending on the purpose of a used computer decide what you are using it for first. A newer computer should be devalued a lot since any warranties usually expire or may not be able to be transferred. Nothing is more exasperating than to fix or buy a computer and have it go crazy due to computer viruses. Imagine walking through an inter city sewer system wearing clean shoes and not wanting to get dirty and how hard it would be. That is what traversing the Internet is like. The more you use the Internet the harder it is to survive without a malfunction. Problems lurk inside a computer waiting till you are right in the middle of something important and then your computer crashes.
Other than Internet problems other problems occur. You want to make sure the owner owned and ran his anti-virus and other computer protection programs. What may happen is you can end up with is a nightmare that he created and got into a new computer because it was doing something weird.
Naturally the older the computer the less value. You can get a Windows 98 machine however unless it is packed with software it may not be all that easy to find software for it. I would not pay more than $20-30 for a complete Windows 98 system. The thing is only dial up at best is going to work for the Internet.
I recently purchased a Windows 2000 model for $45 with all operating pieces except printer. It runs great however I just installed iolo System Mechanic Professional on this computer. Although it operated fine, it still had a ton of problems. Even the hard drive was severely fragmented which I knew it would be. I was first skeptical about this System Mechanic however once I got the computer running well it runs great. The trick is to keep a computer running well. One of the things if you are computer savvy you might be able to use your knowledge to widdle down the cost. Just keep in mind the cost of repairs and the fact a new computer might in some ways be cheaper.
Used printers and used battery backups:
I would never buy a used printer not unless the price is rock bottom and you know its condition. They are just too cheap now days. As far as batteries go unless they are professionally reconditioned and very low prices I wouldn't even glance at an older used battery not unless it is part of a system you are purchasing.
Remember to get all backup disks with used computers if available. Without the disk you won't be able to reinstall a program if it becomes corrupted or totally annihilated. Just keep in mind any and all costs.
About maintaining mouse's that contain mouse balls. When mouse performance gets poor, pull the rubber ball out by twisting piece underneath the mouse. You will want to clean the ball and ball rollers inside the mouse. They get extremely dirty and performance severely degrades. Try Isopropyl alcohol and cue tips to clean your mouse. It is a simple job that doesn't require any special abilities.
Look for arrows under mouse to twist and release the mouse ball.
Once you have the mouse ball removed clean the ball and clean the tracking ball rods inside the mouse. You should see a nasty build up on the rods if the performance has been poor.
