Sometimes when you try to share a folder on an Windows XP computer, you may receive an error message that says "As a security measure, Windows has disabled remote access to this computer. However you can enable remote access and safely share files by running the Network Setup Wizard." This is caused by a local policy setting, read on for the step by step instructions for resolving this problem…

To resolve this issue, modify the Network access: Sharing and security model for local accounts local policy setting. To do this, follow these steps:

1. Click Start, and then click Control Panel.
2. Double-click Administrative Tools.
3. In the Administrative Tools window, double-click Local Security Policy.
4. In the left pane, expand Local Policies, and then click Security Options.
5. In the right pane, double-click Network access: Sharing and security model for local accounts.
6. In the Network access: Sharing and security model for local accounts dialog box, click Classic – local users authenticate as themselves, and then click OK.
7. On the File menu in the Local Security Settings window, click Exit.
8. Restart the computer.

See KB article 913621 for more information on this issue.