Sound like a memory error. Try this memory checking program:http://www.memtest86.com
Memtest86 is a stand alone program that cannot be executed under windows and must
be loaded from a floppy disk.
To install Memtest86:
- Extract the files from the zip archive
- Open the directory where the files were extracted and click on "install.bat".
- The install program will prompt you for the floppy drive and also prompt you to
insert a blank floppy.
- To run Memtest86 leave the floppy in the drive and reboot.
NOTE: After the boot floppy has been created you will not be able to read the floppy
from windows. This is normal.
Let us know the results.