not really, if you're putting xp/vista back on it most of the drivers, atleast enough to get it installed and able to start windows, will be included with the OS. That said, deffo get your NIC/wireless drivers beforehand. Search for them at Acer's website or something and put them on a usb pen or burn them to disk. If you know you can get back on the net after the reinstall then you can then get drivers for anything just by searching.
if it's just slow, you should be able to turn off all that fancy aero interface, and set it to maximize performance over looks. Right click my computer -> Properties -> Advanced tab -> Performance "settings" -> Adjust for best performance. then run antispyware/antivirus/defrag.....