Computer Repair

I just posted my intro tonight. Just thought I'd let you know. I have a question that I hope someone can help me with. I have a small home network consisting of two wired pcs, and 1 wireless. i'm trying to connect a printer so all three can print on it. I've downloaded the printer driver several times. This is hard to explain. I apologize for being longwinded. I was on the phone the other night with HP for 1 1/2 hours and the man instructed me and I downloaded the latest version of this driver. Well I got to where it called to connect the USB cable and I did but this driver never accepted that it was connected. I'm pretty sure that its not the port. So I tried several others. Nothing. After I hung up the phone I cleaned the driver up and redownloaded it. I downloaded it to my computer but from there I can't install it. I guess that's quetion 1 how do I install this driver after it is downloaded to a file. Second what happens if the driver is faulty as I suspect? Third can someone give me suggestions on connecting this printer? Again sorry this is so longwinded.