Homegroup, problem with the LanmanServer

I have just installed a D-Link DIR-655 wireless router where my desktop pc - Acer Aspire M5800 with Windows 7 Home Premium 64 bit is hard wired to my router and my labtop pc - Acer Aspire 7715Z with Windows 7 Home Premium 64 bit is connected wireless.
Everything worked fine until I create a Homegroup, now it takes over 10 minutes when I booting my pc before connects to the network.
After examination of the cases it appears that the service “LanmanServer” hangs.
As soon as I disconnect the Homegroup, there is no problem with the LanmanServer and the pc is booting normally.
Is there anyone who can help?

I havn't heard of this exact problem yet so I would start by leaving the homegroup from both machines.
Homegroup - Leave

After that I would recreate the Homegroup from the other machine this time and see if it works any differently.
Homegroup - Create

If you are still having problems then I would check this Homegroup trouble shooting list and see if you can find any problems.

Homegroup issues

Thanks for your reply
I have already tried both of your proposals without it solved the problem.
When my computer after 10 minutes is logged on to the network works my Homegroup OK
I have verified that my McAfee Firewall is configured correctly and that all necessary ports are open
As soon as I disconnect the Homegroup, there is no problem with the LanmanServer and the pc is booting normally.
I still have access to my other computer on the network, without any changes in my router

Thanks for your reply
I have already tried both of your proposals without it solved the problem.
When my computer after 10 minutes is logged on to the network works my Homegroup OK
I have verified that my McAfee Firewall is configured correctly and that all necessary ports are open
As soon as I disconnect the Homegroup, there is no problem with the LanmanServer and the pc is booting normally.
I still have access to my other computer on the network, without any changes in my router

Thank you for your suggestion, but I have no desire to uninstall McAfee so I drop using Homegroups and will use workgroups instead, it works fine with McAfee.

About the only option I can think of is to change the lanman server settings but this isn't typically required.

edit the Security options\Network security: LAN Manager authentication level policy and select Send LM & NTLM - Use NTLMv2 session security if negotiated. The picture below should help you get there.