Motherboards of computers requiring refurbishment come in a number of shapes and sizes:

Form Factor Use
ATX Standard desktop, mini-tower and full-tower systems
Micro-ATX Lower cost desktop or mini-tower systems
Flex-ATX Least expensive small desktop or mini-tower systems
NLX Corporate desktop or mini-tower systems, integrated 10/100 Ethernet
WTX High performance workstations, midrange servers
mobo

The capability and type of motherboard available tend to define obsolescence with computer hardware, and ideally would be easy and cheap to update. There is a requirement to run the latest versions of software, if a computer is connected to the Internet or a local network of computers. For example Internet browsers need to be upgraded so as to close security loopholes. Older computers therefore may need upgrading to run at higher speeds through the addition of memory chips (RAM). CPUs and chipsets need to be compatible with the motherboard installed in the computer casing. Technical manuals provided by the manufacturer should provide some assistance.

Upgrades of Open Source operating systems may runs in to "hardware" problems, which are difficult to diagnose. This is a problem with running Open Source software, although proprietary software similarly runs better on newer software.

Amazon Books
Image of All About Motherboard: Complete Introduction and Troubleshooting
Author: Pradeep Nair, Manahar Lotia
Publisher: BPB Publications (2002)
Binding: Paperback, 510 pages