C:\WINDOWS\system32\wscntfy.exe The NTVDM CPU has encountered an illegal instruction. CS:0dbc IP:021e OP:65 63 75 72 69 Choose 'Close'to terminate the application. I use Windows XP SP2. I got annoyed by the repeated error messages mentioned above,immediately after logging on to windows. Eventhough I am not so much technical savy, I do search, evaluate & try to solve most of the computer problems pertaining to my laptop. Like that, I wasted few days, but could not find proper solution for the problem. Now, I am able to solve using this:- Diagnose the problem using System Configuration Utility in windows xp. Refer "http: //support.microsoft.com/?kbid=310560". 1. Click "Start", Click "Run", type "msconfig", and then click "OK". 2. On the General tab, mark Selective Startup. 3. Mark "Load system services". 4. Then on the main tab, go to "Services" tab. 5. Find "Security Center" and Unmark it. 6. Click "Ok", Again "OK". Click on "Restart" your computer. If the problem does not occur, you can conclude that it is due to Security Center issue! Now, you have to disable the "Security Center" alert by the following method- •Click Start, Run and type "Services.msc" •Locate the Security Center entry in the list •Double-click Security Center and set it's Startup type to "Disabled". Click "OK". Now, configure to "Normal Startup-all devices and services" using again the "System Configuartion Utility". Note:- Make sure you have a good firewall program and anti-virus with the latest definitions installed, while turning-off Security Center. Otherwise, you are making your computer will be open for all Viruses, Malwares & Spywares!! All the best, Rajendra Halemane.