Please give us more information, where are the shares and what type of operating system is involved. Trying to access shares on XP machine from Windows ? machine. Or Trying to access shares on Windows ? machine from Windows XP machine? Trying to access shares on same machine between Windows XP & VM machine? Disable all the firewalls while you troubleshoot this, if your machine(s) is(are) behind a router they will still be protected. Are the machines in the same workgroup? The results of the Net View may be helpful.
John