Cannot share printer and files

I have a desktop computer with Windows XP, a laptop with Windows 7, and a router. Both computers and the router are configured for internet access. The desktop computer is connected with an Ethernet-cable to the router, the laptop connects wireless. There's a printer connected to the desktop computer, which I wanted to share with the laptop. When I open the Network panel from the Windows 7, I see the laptop and the desktop computer. When I double-click the laptop, I can see the printers installed on the LAPTOP. But when I double-click the desktop computer, an error message appears, which says, that I don't have permission to access that computer, due to invalid password, blank password not allowed, logon hour restriction etc., and I can't see the printer on that machine.(it's shared) Screenshot: http://i34.tinypic.com/20rjipg.png Both computers belong to the same workgroup and network. From the desktop computer I don't even see listed neither the desktop computer nor the laptop, but that's not important. The main thing is, that I want to print from the laptop using the printer connected to the desktop computer. My question is, that how can I give permission the laptop to see the shared printers and files on the desktop computer?

chev65 said:

Which A/V software are you using on these systems cbs362?

If you don't see the desktop listed then something is blocking it.

Both systems are running NOD32, on the desktop computer ver. 2.51(I know it's old), on the laptop version 4.2. On the laptop is COMODO Firewall installed, on the desktop computer Windows Firewall (running XP, built-in). I will check the Windows Firewall on the desktop computer, whether it's blocking the laptop from accessing it, but I don't really think that this is the cause of the problem. Anyway, thanks for your suggestion.

chev65 said:

Most likely either nod32 or the comodo firewall is causing this problem. You will need to either configure the comodo firewall or uninstall it. It usually uses a range of IP's which it blocks unless you allow them through.

Neither NOD32 nor Comodo Firewall is the cause of the problem. When both were turned off, sharing didn't work.

cbs362 said:

chev65 said:

Most likely either nod32 or the comodo firewall is causing this problem. You will need to either configure the comodo firewall or uninstall it. It usually uses a range of IP's which it blocks unless you allow them through.

Neither NOD32 nor Comodo Firewall is the cause of the problem. When both were turned off, sharing didn't work.

Unfortunately turning them off usually won't cut it, as I mentioned earlier you will need to uninstall them completely or configure them to work properly with Windows 7. The Comodo and Nod32 forums might be useful for the proper configuration.

You would be far better off to get sharing set up and working before you install any type of A/V or third party firewall. That way you will know if the installed A/V's are causing the problem or not.

There are a few tricks to getting sharing to work with XP but until your A/V's are uninstalled it's impossible to know if you need to use those tricks or not.

One method is to turn off simple file sharing on the XP machine, the link below explains how.
http://compnetworking.about.com/cs/w...t/winxpsfs.htm

Another method involves a registry adjustment on the Windows 7 machine.

Type in regedit into your command prompt then navigate to the following key.
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System
create or modify 32-bit DWORD: LocalAccountTokenFilterPolicy
set the value to: 1

This exact problem with Nod32 and Comodo has come up so many time's I've lost count. Pretty much all real time A/V's and third party firewalls can cause problems with sharing.

As far as USB printers are concerend, in my opinion they are inherently problematic. It's better to use a network printer. But using the method in the link below might work for you.
XP to 7 Printer sharing