Invalid Boot Diskette

I have the most annoying problem ever. My brother erased his hard drives, and so it is up to me to install XP again. HE uses an old Dell dimension L388 or something. It has the worst Bios Ever. Whenever I put in a bootable CDROM and change the boot order, It says " Invaid boot diskette in A:" I can't get anythere without a boot diskette so I got one for his old ME system. I can now Start in DOs. So I use a folder on the winXP CD called I368, and open a file called winnt, which should allow me to boot from my hard drive and continue his xp instalation. I restart after running the file and It says" invaid boot diskette in A:". even if I unhook the floppy, I will still get this error message. I changed the boot order again, putting everything possible on, except the floppy. I still get the same message. Could someone please help me? Thanks in advance.

 

I gotta admit, you had me starting blank at the screen for a few seconds! Ive had 4 old dells but not that problem. Dells have very limited bios config. try turning off the floppy drive in there. If ya cant do that, turn off swap floppy if ya got that. Also im sure ya tried it, but in the boot order, put floppy last. Also, this sounds pointless but we can try anything at this point. How old is your brother. I know some kids (my cousins) have put pokemon cards in teh floppy drives and so forth. ;-) Take apart the floppy and see-clean out the dust, plug it up and see. When booting does it light the light on the floppy?. If its pretty old, it may even seek the floppy. Also, i just thought, can you disable the whole floppy controller?! Disable whatever floppy junk ya got and see. post back with ANY info you got.

Edit: I just googled that L388 dell you said he has...I cant find anything in coherent english that is of any help...can i get some more info on the model? thanks