outlook 2003 runs fine here on win7 64. have you tried running it as admin?
+1. If running as admin works, find the Outlook.exe file in the Office install folder and right click on it. Enter the properties menu and go to the compatibility tab. Check the box to run the program as an administrator. This will make the change stick, so it's run with admin rights every time you open it.
Take ownership of the Office install folder, then change the security permissions on the folder to give yourself full control rights.
I have also taken ownership of the office folder and also changed the security permission of outlook for full control but it still comes up with the same error when i try to send and receive.If i send only, it works ok.
I have also uninstalled and re installed office.