Your printer and com ports are usually the culprits. S ystem B ackups CD Roms provide an alternative to making exact duplicates of Root and Windows file systems. Another good idea is to make a bootable CD so data can be transferred in case of corruption. Items to check are cmos settings from SPP to EPP etc. Reinstalling driver, software for your printer will usually correct problem.
Indicators are systems that lock up on a regular basis.
Substitution is the best and the quickest way to resolve these types of occurances. True, they may work normally for a short period of time but will, eventually, develop intermittant parity related symptoms, and usually fail. Remember treat-memory with great care. The only complication is that if your old board is an AT style case, you will need to replace the power supply with an ATX that physically matches your existing supply. Another alternative is to replace your tower altogether.