Hi, Thanks for the suggestions, I shall look into them soon (I'm a bit busy at the moment with a big coursework project). Sebastian Schneider wrote: Probably not a good idea. If the power fails during the flash, chances are that the laptop will keep running from the battery. Very good point, I shall charge it and leave it in. Sebastian Schneider wrote: I don't believe the BIOS is the problem of your recurring start-up trouble. If it was, the boot sequence should fail every time. Really? I did some research into the issue, before I came to the conclusion it was my BIOS, and found this PDF[^] which talks about the introduction of 48bit addressing support in ATA-6. On page 6 in the "Solutions exist!" section: Solutions exist! Most motherboards have built-in connectors for the hard drive and CD-ROM drives. 40-pin ribbon cables connect the drives to the motherboard. These motherboard connectors are often labeled IDE Channel 0 and Channel 1. They are also called Primary Port and Secondary Port. Both are the same. The system BIOS auto-detects the hard disc drive and issues an inquiry to get the drive's number of LBAs. The largest number it is prepared to receive may be 137GB. In this case you might check with your system manufacturer for a BIOS upgrade. Many namebrand systems have the ability to "flash" the BIOS with new firmware. This is what my BIOS is doing. It's reading the size of the hard drive as 137GB exactly. Also from the same page of the pdf: Solutions exist! Without proper support, writing or saving data past the boundary line will wrap around to the front of the file system and overwrite all of your file system information, effectively erasing your drive. This is the part that made me think it's the problem I'm having - I exceed the 137GB limit and end up writing data over the MBR, etc. Please say so if you still think I'm wrong about this, but to me it looks like this is the issue I'm having Many thanks, Will. “Accept that some days you are the pigeon, and som