Fallout 3 and vista

specs of both laptops would help, but really most laptops ain't for gaming.

Your Laptop probably isn't up to standard. To make a fair and accurate determination we would need to know the system specs of both computers. A Laptops are built to use the least amount of power. They are not built to be powerful gaming computers (except for a very few) so comparing a Laptop to a Desktop isn't being reasonable.
I have Vista on my main computer and XP on my secondary. My Vista Computer get's turned off only when my cat accidently hit's the off switch which is about once every other week or so. My XP needs a reboot every day. Yes, both computers run pretty much 24-7.
Comp 1:
Vista
Phenom 9600
790FX
3870 Graphics
4 GB 1066 Ram

Comp 2
XP
AMD 5400
780
4830
2 GB 1066 RAM

To be fair maybe your Laptop just barely meets specs while your Dads exceeds his. RAM can make a substantial difference as can Fragmentation of a HardDrive. As one guy pointed out above your Drivers may need updating.

To think that Vista is the issue is probably going down the wrong road. To be fair my sons computer (computer 2) should kick the hell out of mine (comp 1) but in practice mine just runs better. I keep my drivers up to date, my drive is defragmented, I use 3rd Party Programs to Uninstall, and quite a bit more. When it comes down to which computer is the better one in the house everyone in my family will say mine is. Most people on this board would say my son's is. But Reality is always different. The little things can add up and make a difference. You have probably just experienced this.