When you are choosing the best used CPU or computer processing unit, you have to look for one that does not contain any leftover personal files or viruses. You also want to know which operating system is currently running on it. After you find out more information about the used CPU, you can negotiate a price with the previous owner.
Most used CPUs are going to have someone else's personal files and programs loaded onto the computer. Be sure that all these have been removed by the original owner. It is also important that the used CPU does not have a virus or spyware on its hard drive. Ask the previous owner to run a spyware and virus protection scan before purchasing the computer.
Ask which kind of operating system is on the used CPU currently. It may be an old operating system, and you want to be sure it can be upgraded to a newer operating system if needed. You can also ask for the backup disk for the operating system or any other disks that are associated with programs on the used CPU. These disks are needed if you ever have to erase the computer's hard drive and load all its programs back onto it.
The hardware of the used CPU includes the disk drives and the plugs that are visibly seen on the outside of the computer. You will want to check each plug and the drives to be sure they are functioning properly. Ask the owner of the CPU if he or she have ever had to replace any parts of the computer and what was used as a replacement.
Some people sell their used CPU as a package deal and may include a computer monitor, keyboard, or mouse with the computer. If you need the other parts, then ask if the owner will bundle the entire package together or give you any extra parts to go with the CPU. If not, you may have to purchase the other computer parts if you do not already own them.
If the CPU is in good shape, then be sure to know what the cost is for a new one of the same model so you know how to negotiate the price. The cost of a used CPU will depend on how new it is and what parts and programs it contains. Researching the price of different computers on the market will help you to pay a fair price.