Can Anyone help me please

I have 4 Rigs all sharing the same 1mb DSL via a switch no problems there but whenever i try to acces the shares on one rig (Called Flatty) i get the following error

No matter what i have tryed i cannot change this.

The network is setup correctly and i have ran the Setup office / home network wizard untill im blue in the face but still the same.

OS WinXP Pro Sp1 very up to date on all rigs

Rigs

Flatty P3 750

Bigboy XP1600 \

Birdy 2.8 PIV | Can all see each other but cannot see / access Flatty

Ralphy XP1800 /

anyone?

i have been here

Administrative Tools->Local Security Settings->Local Policies->User Rights Assignment, right-click on ''Access this computer from the network->Properties->Add Users or Groups

and added all the rigs that need to access the shares but i then get the following

Failed To Save Local Policy Database

i even tryed it in safe mode with full admin rights and was still unable to get this working!

can anyone help me here?

Any firewalls or antivirus running? Panda antivirus stops you accessing shared files/folders if not configured properly.

Edit: Also, check if the XP firewall is on.