MS will tell you it is a driver or hardware issue. In "MY" case, it was RAM that was becoming unstable and would not work with the other stick anymore... (YMMV) Here is a KB article NOT "too related" to WHEN you get this problem... http://support.microsoft.com/?kbid=311564 On the stop message, there is usually a string of numbers and maybe a module or file name. Sometimes looking up a certain part of those numbers can help narrow it down... If you can get a digital camera picture of the error screen and post it somewhere, someone might be able to help more... Rick Glazier From: "James Daly" >I have an Abit KD7 motherboard with AMD Athlon XP 2000+ /KT400. > > I have been getting, with increasing frequency, a system halt (IRQL_NOT_LESS_OR_EQUAL). > > Does anyone have experience with this (type of) problem? PCBUILD's List Owners: Bob Wright<[log in to unmask]> Drew Dunn<[log in to unmask]>