Good morning, I recently bought 3 TC1-MEM-128 PDP 128mb pc100 sdram 16x64 168 pin dimm memory modules. I have a pc with 4 memory slots. I already had one (1) 128mb pc100 sdram installed. After I install the 3 new memory cards, i only register 320mb of memory when i boot the computer. So, basically, each of the 128mb cards i just purchased are only actually registering 64mb. According to my mother board documentation, any pc100 memory will work. I appreciate any help. Thanks !!! Joe The NOSPIN Group Promotions is now offering Mandrake Linux or Red Hat Linux CD sets along with the OpenOffice CD... at a great price!!! http://freepctech.com/goodies/promotions.shtml