As part of NTLP's closing, we are giving away a lot of used technology items. There are a couple of common questions that people have with older technology items, especially if the original packaging and accessories aren't all available. Here are a few answers.
If the computer originally came with an operating system pre-installed, the new owner of the computer is entitled use to whatever system the computer originally came with. For older computers, this might be Windows XP or Windows Vista. If the old owner of the computer had updated it to a more recent operating system, and you don't have the license to the upgrade (the upgrade license was probably non-transferable), you'll need to either re-install the original operating system or purchase your own copy of the newer operating system and do a fresh install of it.
There's probably an activation key for the original operating system on a sticker somewhere on the computer. If you have the OEM (Original Equipment Manufacturer) disks for re-installing that operating system, you can use them. You can actually use any OEM disk for that operating system as long as you have the activation key that goes with that device. If you can't find disks, you might be able to order recovery disks from the manufacturer for a small fee.
To install the operating system from a disk, you'll need to boot the computer from the CD instead of allowing it to boot normally from the hard drive. Sometimes you can hit a function key during the boot sequence to interrupt normal system start-up and get a boot menu. Sometimes you need to hit a function key during the boot sequence to get into the ROM setup configuration screens and change the boot sequence to make it boot from the CD drive. Watch the screen while the computer is starting out to see if there's a hint, like "Hit F2 to enter Setup." If you can't figure it out, go to the manufacturer's web site and look in the 'support' area, or Google your question.
Some computers, instead of coming with OEM disks for re-installing the operating system, have a recovery partition pre-installed, and you can interrupt the boot sequence to re-install the original operating system from the recovery partition. Again, look for hints on the screen during the start-up sequences, or go to the manufacturer's web site and look in the 'support' area for information, or Google the question.
If the system recovery options leave you with an older operating system and you want something more recent, you'll have to purchase your own copy of the operating system (Windows 7 or Windows 8, for example) in order to have a valid license. Except for the operating system that came pre-installed on the computer, licenses are non-transferable.
You might also consider installing Linux. Older computers that run very slowly with Windows can often be converted into acceptable Linux computers, especially if you're mainly interested in using it to access the Internet. There are various free versions of Linux that you can download for installation.
User's Manuals, Drivers, and Replacement Parts
Find out the manufacturer's name and the model number for the item. Go to the manufacturer's website and look for a 'support' area, and search on the model number. Or just Google the item, including the manufacturer's name, the model number, and the item description in the search phrase. (For example, "Epson PowerLite S3 projector") You will probably be able to find a complete description of the item, downloadable user's manual, downloadable drivers and updated software, and ways to order replacement parts.
If a computer or printer doesn't work, check the 'support' area of the manufacturer's website to see if you can figure out what's wrong. You might be able to order a replacement part or fix a configuration problem and get it working. If not, the item might still be useful to you if its parts can be used as replacement parts for a similar item.