That will depend on the operating system. If it is an NT system (NT4, Win2k,
WinXP) you will need an account on the other computer that matches your same
user name and password and give that user account or one of the groups that
it is a member of permission to access the share. This will need to be done
for both the Share permissions and the NTFS (Security) permissions if your
drive is formatted NTFS. This is frequently done by leaving the Share
permissions as Everyone with Full Permissions and just adjusting the NTFS
permissions, but there are times it is advantageous to adjust the Share
permissions as well. If your OS is WinXP Home Edition, it tends to just use
the Guest account for all of the shares and therefore doesn't get as
explicit.
If you are running Win9x (95, 98, ME) you need to make sure that the
password on the share is the password being passed in the connection
attempt. Also, there are some interoperating problems with NT and 9x, most
of which there are patches for.
If you have any further questions on this, I suggest one of the newsgroups
for your operating system. They can give you better details on how to do
this.