Windows 7 - Win7 Cannot join homegroup wired and wireless

Just got new house, and putting together a new Windows 7 homegroup network (new isp, modem & router)
I have the wired computers(3) connected through the router to homegroup called network3. And they can share file, and printers just fine.
The wireless laptop connects to the router though a wireless connection called 'wireless network' it can get on the internet just fine. but it (laptop) can't join the homegroup the wired computers are connected to. It ask to connect to the homegroup by name (network3), when I click "choose homegroup and sharing options" in the Network and Sharing Center screen. I enter the password that works on the other wired computers, but them I get the dreaded balloon saying "Wndows can not set up a homegroup on this computer " pops up, then just sits there.
How do I get the laptop to join the homegroup? There is no other network shown other than 'wireless network'
Thansk

try this first: make certain all computers are scychronized to the same date and time.
I know that sounds like a "given," but I had a smiliar problem in joining my workgroup.
The Windows 7 laptop could see the other computers but when trying to connect, it asked
for the network password & identified my computer as belonging to a domain (which
it wasn't).
I tried everything. My time was the same on all the systems. Then I noticed the Windows 7
system was a day off. I fixed that and walla! Windows 7 could not only see the other systems
but also, connect--a two week search & trying to connect, solved by the simple
thing of making sure all computers had the same time & date.
Also, you need to have the "everyone" group active, with full rights.
And user accounts with the same name and password on each system.

If those things don't work, hopefully others will answer with the answer.

Bob

Good point about the time. The laptop was off in the time by 2 hours. I also found that the old homegroup I had was still on a couple computers.
I went and removed/deleted any old homegroups from all computers. Did a reboot on all, just to make sure. Then started a new homegroup, and all is almost fine. All the machines can see eachother.
But printing does not work. From the printing and devices screen on all the computers, I have added the main printer, and deleted any other real printers that were previously installed. In the computer that the printer is USB connected to, I set the properties for sharing on for everyone. So now all computers can see the printer, but can't print to it. When going back to the homegroups screen, there is a button to install a homegroup printer. When I click it, nothing happens, on the laptop, and one wired computer. On the other wired computer after about 5 minutes, it started to download drivers for the printer. But that computer already had drivers. It did not look as though the just download driver files were installed, and I can't find where they were downloaded too. I also tried MS's Mr. Fixit, and it reported no printer problems.
suggestions on printer issue?
Thanks