Can't share printer on local network (0x00000012 error)

Hi all, I have a weird problem. And also complicated, 'cos not even my CISCO Network teacher has been able to give me a solution. I think I need some smart people here

The thing is that I can't share my printer (connected by USB to my PC) with my laptop on another room, over the local network (in Win7 the name is Home Group).

The printer model is not relevant because time ago I was able to do what I'm trying now.

All my configurations are OK, at least the basic ones, because there's definetely something wrong with my PC, and here's why: if I take my laptop and put it next to the printer and connect it to it (by the same USB cable), I can access the printer with my PC, while it's been shared by the laptop.

That proves that the internal network is fine. Also, all the configurations of the printer and also of the home group are literally same in both PCs, the big one and the laptop.

Both PCs run Win7. I have tried this, Connect to printer error - Microsoft Windows Vista Community Forums - Vistaheads, but it didn't work.

The printer is also properly installed on my PC, it is not a driver problem or something like that.

My AV is ESET ESSBE 4, but I don't think it's related, because I have tried deactivating its firewall, and also, on the laptop the AV is the same and the
printer did work.

The services are also equal in both PC's now. I have even tried changing the network adaptor on my PC (from Ethernet to Wifi). Nothing.

I recently had problems with the home group, but they are solved by now. I guess the source of the problems is the same, but I don't know where else to look.

Does anyone have a clue of what' happening here?

Thanks in advance.

The firewall is up, just fine. Tried ALL of that post (the 90% of the stuff was already done by me) and the error persist. Remember, is a different code error compared to the one on that post.

Help!

EDIT:

Now I can add it with the local port trick. But that's not OK to me, I mean, from the laptop the priter shares just fine. It isn't supposed to make you write manually all the paths. So again, something's wrong with my PC and I want to know what and fix it.

Hope anyone can help me.

EDIT 2:

Never mind. I mean with the text I wrote here about a problem with the queue. I still need help, I am like in my first edit.