You where correct on the first code I posted didnt work because of the letter in the string. Since he only wants to check for Window 7 the most simple way in VB.net would be to use My.Computer.Info.OSFullName, this produces this return on my computer Microsoft Windows 7 Ultimate Then we check to see if windows 7 is in the string. Since he ask for VB.net and not any other language maybe you should post the correct langauge. I misread your first code and thought it was Vb.net sorry I am dyslexic so reading and wrighting is hard on me some times. Button1 Click Is set to 6.1.7600.1 the wrong version to produce the error message using >= version should be 6.1.7600.0 If you want to test this with a simple vbs script using WMI and >=