Look at this - taken from: click here
"Save Password" option on connect box is greyed out.
The save password option on the "connect to" can be unavailable for two reasons.
1. The Client for Microsoft Networks is not installed/damaged:
Install / reinstall Client for Microsoft Windows. Remember to fill in the Computer Name and Workgroup fields in the Identification field. You can put anything in here but it's best to keep the entries less than 8 characters.
2. The password file is damaged:
a. Do a search for *.pwl. b. Delete all those. c. Reboot the machine. d. When the "Windows Logon" login box appears enter a username and keep the password field blank. e. Press OK to confirm the blank password. A new username.pwl is [automatically] created.