booting problems

First check all cables to hardware,especially the hard drive cable to the MB

When booting listen to hear that CPU and Power Supply fans are working

Open the Computer and check the memory modules to make sure they have not crept out and are seated in slots properly

Using a Windows 98 startup disk insert in floppy,boot computer,select to run setup without cd rom support,at command prompt type fdisk /mbr,reboot

Check the video drivers,they may need updating

If none of the above works,try fdisk and reinstall the OS

Have you checked the Compaq web site for info on this. The entire Presario series has a number of known boot problems and the last time I was on theri website they listed a number or work arounds for each model.

I have found only one way to make a Presario work properly. Win98 boot disk, TOTALLY wipe the hard drive, reformat and load Win98 then Win98 SE. Killing off the Compaq info tored on the hard drive seems to allow them to perform better with Win 98; well it do on the three models I have had to fix.

Found on 4716 F8 worked one way and F10 worked another, but you only have 2-3 seconds with a flashing cursor in the upper left corner to force the change boot request. Hit the key too early and gives a keyboard error.
BTW - When it felt like it escape even worked.

Download the latest bios/cmos from the Compaq web site, extract onto disks and install per directions on Compaq's site. Could be a corrupt bios, if not at least you will have the latest version running on the machine.