Suddenly unable to connect to network share

A strange problem appeared suddenly on my home network.
the network is comprised by a workstation class Pc, with Windows 2003 Server R2, plus 2 Windows 7, 3 Windows XP (1 of thema a laptop) and 1 Ubuntu Linux PCs.

I have 2 network shares on the server which are mapped on the same Disks for all PCs.

This has worked without a problem for 2 and a half years or so.

BUT since last night whenever i try to access those network shares on any of the 2 Windows & PCs i cannot and i get a repsonce about the password being wrong.

it obviously isnt, i can connect with no problems from any of the 3 Windows XP PCs or the Linux machine. I can allso login normally, or connect via Remote desktop. The password is ok.. something else is the problem , but what?

does any of you have any pointers?

ooops sorry i should have mentioned that.

Windows firewall on the Server seems to be configured properly ( as it was before..) , but just to check it I tried connecting with it turned off... nothing changed.

I must also say that i can connect without any problem to the network shares on the XP Machine, and the Ubuntu one from the two Windows 7 PCs. Nonetheless i turned Windows Firewall off in the W7 Pcs, but to no avail, i still cannot connect.!

I can connect to any machine from any machine, except from the Win7 ones to the 2003 server.

koumooo said:

I can connect to any machine from any machine, except from the Win7 ones to the 2003 server.

This requires that you change the lanman server parimeters in order to get Windows 7 working with older servers. Do these adjustments on the Windows 7 machines that need to connect to the server.

Control Panel - Administrative Tools - Local Security Policy

Local Policies - Security Options

Network security: LAN Manager authentication level
Set to Send LM & NTLM responses only

Set the Minimum session security for NTLM SSP
Disable Require 128-bit encryption

The screen shots below should be helpful.

Reboot all machines after making the adjustment.