I'm running Vista 64bit on an AMD based system. I have an HP laserjet 1320 and a Canon Pixma MP950 connected to this computer... and I can't find drivers for either of them.
Go to Hp and download the drivers, I also own a hp my model is HP PhotoSmart C5180, if yo ucant find your drivers, then call or email hp and ask for the nearest drivers to your printer they should tell you that.