I'm not sure where the option is that you're looking for but I believe ALT P will let you go to a new bios page.  That said, the bios is very intuitive as it lists the directions that you need

I have never seen the BIOS pages on a 5100 series, but the C-series Laptops all had that option by setting PS/2 Mouse in Pointing Device on page 3 or 4 of BIOS setup. That disables the Touchpad if a PS/2 mouse is connected. Default is Touchpad/PS/2 Mouse and both work at all times. F2 will get you into Setup, but then read the directions on the bottom and right side of the pages

Latitude C840(converted from Inspiron 8200)
1.6mhz Pentium IV
512mb PC2100 DDR SDRAM
40gb Hitachi 7200rpm-HTE726040M9AT00-UDMA5
HL-DT-ST-GCC-4240N CDRW/DVDROM in Fixed Bay
LS-120 SuperFloppy in ModularBay
Windows XP Pro SP2
FanGui 2.20
nVidia GeForce2 Go 32mb Video Card
15" SXGA LCD
C/Dock II 

Message Edited by leduke30 on 05-01-2005 03:11 PM

Apparently not, and I would surmise that is the reason he can not disable the touchpad.  I guess Dell decided a USB mouse was good enough and connecting one of those does not disable the touchpad even on models with that Setup option. Thanks for the heads up, nemesis

Message Edited by leduke30 on 05-01-2005 05:18 PM

Thanks all for your reply...looks like 5150 does not have option to disable touch pad...heard from Dell and best I can do is change the sensitivity...darn...again thanks for your inputs...great education

you can always disable it in device manager...  not as quick, but if you're using the mouse for extended periods, it's an option