Dell Latitude D505 drivers

[#1]

My son caught a virus and a couple of trojans on his Dell Latitude D505. I cleaned them off, but the system was well and truly trashed. I reformatted his HD and reinstalled windows XP. Unfortunately his drivers have all disappeared, and I'm unable to get a decent screen resolution. There are possibly other items which need drivers. I tried looking at the Dell website, but they require the Asset tag to positively identify the PC. This has been damaged some time in the past and is only partly visible. Can I just download install *all* the drivers on the Dell site, or does chaos lie waiting if I do that?
Any other advice gratefully received. Except that he can't afford a new PC  so please don't suggest that

[#2]

The drivers on this page should work: http://support.dell.com/support/downloads/devices.aspx?c=us&l=en&s=gen&SystemID=LAT_PNT_PM_D505&os=W...
If it's a poor screen resolution it'll be the video drivers that you need to update, there's two different versions it seems so you might need to download both. Don't worry if you get the wrong one though, as far as I know nothing bad will happen - the driver install will just fail and you'll need to try the other one instead.

[#3]

Many thanks Matt

[#4]

You'll also need to install the chipset, audio and network (wireless) drivers.
Dell laptops should allow you to reset the computer to its factory state from information on a hidden partition that you access by pressing f11 (or sometimes f8) as the computer starts.  If you reformatted the entire hard drive you will have lost this hidden partition but if you had used this factory reset option you wouldn't have needed to install drivers.

[#5]

Thanks Reed, wish I'd known that before I started 

[#6]

Hi.  the systems service tag, should be displayed in the BIOS as well. i think for dells press F2 to get into it, as soon as the dell splash logo appears when you switch on.

[#7]

Thanks Penfold, I see it there, now I've d/l'd all the drivers I could find 
It all seems to be going OK now, just a long slog