Windows 7 file sharing

[TRexx]

I've been sharing files & printers between a Windows 7 Pro 64 Bit PC and a Windows XP PC for months.  Suddenly the XP box can't see anything on the 7 box.  If I reboot 7, everything is OK for a while ( a few hours ) and then suddenly the 7 box seems to block all requests, If XP tries to open one of 7's shares I get "An error occurred while reconnect H to \\hostname\sharename". If I try to map a network drive, the 7 box appears, but none of its shares. Also when I try to Ping 7's IP address, it times out.

I assumed a firewall issue. I use Comodo.  I killed Comodo but the problem persists. I also verified that Windows Firewall is off.

I have another box running 7 Pro 64 Bit on the same network, also running Comodo.  XP can see all it's shares just fine and it can see the shares on the first 7 box.  It replies to Pings

Any idea where to look next?


Update:

A coworker suggested a registry change

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters

"Size" was set to 1.  I changed it to 3, rebooted and 10 hours later XP can still see 7's shares.

[Richardk]

I did a little bit of poking around and while this may solve your problem I’m amazed how obscure this fix is. I found several sites that gave this solution but you had to know what to look for and only one or two sites had any explanation of the what / why this works.

This felt like the early days of digging for a solution.