Downgraded to XP, now no drivers

I have the Toshiba Satellite A100-VA3, model # PSAANC-VA305C. It was preinstalled with Windows Vista Home Premium and I'm sick of Vista (plus I lost the recovery disc) so I installed XP. Now that I don't have the vista disc, I can't go back even if I wanted to... it would be perfect since XP works fine, but:

- No sound - drivers don't work; can't find any compatible ones online.
- Ethernet doesn't work.
- Wireless (internal) doesn't work. I'm using my external D-Link card to browse the web.
- The additional touchpad features (ex. virtual scrolling) don't work.
- The modem for connecting to 56k connections doesn't work.

I love Windows XP - it's much, much faster and more stable than Vista but I really need these drivers. I think since my system was preinstalled with Vista, there are no XP drivers available, although I installed Ubuntu on it yesterday (but couldn't use it for other reasons) and everything (ethernet, sound, wireless) worked perfectly (except the dialup modem) without the need to install ANY drivers, which is kinda weird since it won't work on XP.

What can I do? Can someone help me find some new drivers for XP?

As it does not work now, do this. Go to Device manager, delete everything with a yellow on it. Then go to contro panel, select add hardware, follow the instructions, and all should be well.

It doesn't work. Add Hardware says that it can't find the software/drivers that it needs to install them and it just reinstalls them with the yellow hazard sign and they don't work.