Is Vista 64 Bit causing Network setup problems?

[#1]

Firstly I am a new recruit to plusnet, having recently swapped from TalkT..k, and have 2 problems that I thought somebody might help me with, having read a few of the posts.
The first problem is a broandband speed issue which I will post in the relevant area.
The second is:
I recently had to purchase a new PC, so went for a more powerful one it has 4GB of memory and came with Vista 64, I am having problems with harware not having drivers for vista 64, but as they become available I will sort those issues out hopefully.
I have a home network through a modem router which is a new F6D4630-4v1the main computer is connected to the router via an ethernet cable, and will connect to the internet, however it will not connect to a laptop via the network I have set up using Vista's set up program and a memory stick etc
The first Laptop was purchased at Xmas and is used wirelessly running Vista Home premium and will connect to the internet and will also show the main computer on the network page along with other devices connected, however when you double click to connect an error message occurs saying something like the name is spelt incorrectly, it offers to diagnose problems but this is no help.
I have a secong laptop that is running XP and is a few years old and has been on the network for ages, this also connects to the internet and also the first laptop, the first laptop will also connect to it.
No matter what I have tried I cannot gain access from any of the laptops to the the main PC through the Network or vice versa.
I have tried to read articles on this and ensured all relevant folders are shared, each PC has usernames and passwords, but still I cannot get it to work.
Hopefully one of you kind members can help me
cheers

[#2]

Just rebooted my PC to switch back from Windows 7 64 bit to Vista 64 bit.
I didn't have any problems so can we go through the basics
From the main computer (assuming this is the Vista 64 bit machine) can you see the other computers on the network.
It should be something like the last picture with any of the other computers showing
If you go into Control Panel then Network and Sharing Centre on the main computer does it look like this and if you click on Customize does it look like the second picture
Finally try disabling the firewall on the Vista 64 bit machine

[#3]

Thanks for the initial response
I am not at home so am having to call home to get details
Looking at your post ref Network etc
If I look at devices attached to the Main PC (Vista 64) it shows the router, a network printer, and another device, but it does not show any other PC's eg the laptops
However If I look at the laptop it shows the main PC but will not connect to it, and obviously if it is seeing it, it knows it's there because I haven't manually put any settings in (that I am aware of)
When I go to the Sharing & Discovery Page on the Main PC and click on customize, it doesn't look the same as All the check items are on
I cannot instruct mu wife how to swith off the firewall over the phone, so will have to this at weekend
cheers

[#4]

It is possible it has the wrong workgroup - this shows how to check on Vista

[#5]

I don't believe it's the wrong workgroup, as they all the show the same on the PC's
And the first laptop shows the main PC in the Network, but won't log onto to it saying the name is spelt incorrectly etc
But obviously that can't be true because it is auto seeing the computer
I will have to spend some more time at weekend going back to basics, which I have already done once to no avail
thanks