Hi, On a 486 I think I would start by replacing the CMOS battery. Any machine of that age more than likely needs that, unless of course it has been done recently. Brad Loomis Morro Bay, CA -----Original Message----- A friend's PC is failing to boot. The hard disk is identified quite alright but after that it gives an " invalid disk replace and press any key to continue" error message. Pressing a key does not solve anything. One interesting thing is that it cant even boot with boot disketes. I did set the boot sequence starting with A: then C: The PC is 486, win 95, 24MB RAM and 800 MB disk space. Chilangisha Changwe 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