The slots 1 & 2 you are referring to should be closest to the serial port. If there is a BIOS update available for the computer install it. Test the two 1GB DIMMs one at a time to see if one works and one fails. If that happens then you do have a bad DIMM. If they both fail then there is more to it than that. In which case you should contact Kingston tech support by phone, (800) 435-0640, to verify if the memory is indeed authentic Kingston ram. Many counterfeit parts are being sold on Ebay these days.