Dell Dimension 3000 skips Dell splash screen and BIOS

Hi all,

I have a spare computer from work, but I do not know the password to log in, and so would like to wipe it. Ergo, I decided to try and boot the computer using a USB thumb drive with Ubuntu on it, so as to wipe the windows partition on the hard drive and then install Ubuntu. The computer boots normally to the Windows XP login screen. When I press F2 or F12, there is no display output. I have tried this with a variety of monitors and with two D-SUB cables (one at a time). These are the Samsung LT27B551EW, LG 27EA63V-P and Dell Rev A00. None of them show either the Dell splash screen or the BIOS screen. I have tried pressing F2 and F12 at strategic intervals (every 2 seconds) but still there is no display output. I also know that I was able to access the BIOS on the same computer a few months ago, but I forgot which displays I used then - I had to wait for permission to wipe the hard drive.

I have also looked up this problem in a number of other places, and found that this is supposedly due to an incompatibility of some kind with the monitor. However, I am not sure as to how I might go about fixing this issue, as I do not have any other monitors or cables which work with the Dell - all my other cables are either HDMI or other sorts of cable which do not plug in to the Dell. If there is a way to use the hard drive and wipe it without accessing the BIOS I would also be grateful to hear about that too.