LAN access problem

[3dsmaxed]

Hi all

i have some problem in my network

I have 5 - 6 computers on local network out of which all are accessible via lan but my laptop is having some problems.
it shows up in the workgroup computers . if i try to access it it sometimes goes into the next step but sometimes it gives me error " \\computername\drive letter is not accessible. You might not have permission to use this network resource.Contact the administrator of this server to find out if you have access permissions."

so i am sometimes even able to go into a drive of lan computer but then it again gives that message if i try to go further.

it happens if i try to access any computer from my laptop or vice versa.

All other machines are working fine and working on same perating system that is win xp.

Where can be the problem

Thanks