I have a HP Deskjet 2050 All-in-one J510 Series, but I can't scan. Help?

Every time I hit "scan"... my printer will "Prepare to scan" but then it stops. A window appears that says "Scanner communication cannot be established." I tried re-installing but it still won't scan. I tried it on my sister's laptop and it worked fine. So what do I have to tweak in my laptop to make it work? :(