Check your other post.
You may be running into a motherboard failure problem.
The easiest albeit not the cheapest sollution is to call EMI. They sell industrial grade replacement computers that will replace most any of the OEM computer motherboards. Otherwise, any local service tech who knows how to service DOS based computers should be able to service your computer - if you can find parts.
Your upgrade options are EXTREMELY limited. Why? Because of the need to have an ISA slot in order to fit the BMDC card which is the heart of the Eztrak system.
ISA based AT motherboards are readily installable into the machine. Make sure you you use a 386, 486 or a Pentium but do NOT exceed 133mhz in speed in anything you get. Also, make sure the BIOS is properly reset to match your current system.
DO NOT GET FANCY WITH NEW PC BIOS SETTINGS!!! Make sure that you do NOT engage the LBA option in a new motherboard if you install it.
You might want to check your power supply and hard drive. A funky power supply and a hard drive that are going south can cause all kinds of wierd problems.
BTW: 9 years on the same motherboard and hard drive are an ETERNITY for PC based systems. Be thankful you got 9 essentially trouble free years from the machine.