Hi everyone, I am a new user of this forum. i have a problem on my pc. I have a payroll system that runs on 16 bit MS-DOS system.... recently it has the following error message:- c: Docume~1\Admin~1\Local~1\temp\cn911.exe. The ntvdm cpu has encountered an illegal instrustion. CS:05cd IP:0169 OP:63 68 61 72 73 choose 'close' to terminate the application. after i close it another message come out, The request to end selected 16 bit task has timed out. The win 16 subsystem may be unstable. Press OK to terminate the win16 subsystem or cancel to leave to running. Another time the message Cn912.exe has encountered a problem and need to close. We are sorry for the inconvenience. Is there anybody to help me to settle this problem.. I am not an IT technician, just an office administrator. My knowledge of the pc is only on the operation side. And the vendor for my payroll system wanted me to upgrade it to window 32 bit... but it cost a sum of money.... Help!!!