From DD-WRT Wiki
While many sources say to turn off security settings, clock was unable to find the specific security settings that were being referred to. These are the settings that worked for me using Windows Vista, but they may not be the best. My hope is that others will help to flush out this page.
 Security Settings
- In Vista, to disable security:
- Go to Control Panel -> Security -> Security Center. You will want to use that screen as a gauge of your progress.
- In Control Panel -> Security, disable your firewall.
- You'll have to go into Tools and Options under Windows Defender to edit and disable that.
- Turn off User Account Control under "Other Security Settings."
 Other Vista Notes
- Please be advised that you may also have to: