“The address of this site is not valid” Error Message

If in Outlook 2003 when you click on a hyperlink and get the following error message

The address of this site is not valid. Check the address and try again

You need to get the latest service pack for Outlook. To get the latest service pack for Outlook 2003, click on the link below.

How to obtain the latest service pack for Office 2003

You also fix the error manually, just follow the instruction from Microsoft.

Exit all Office 2003 programs.
Click Start, click Run, type regedit, and then click OK.
Locate and then click to select the following registry subkey:
HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Common
After you select the subkey that is specified in step 3, point to New on the Edit menu, and then click DWORD Value.
Type HypAlternateResolveToRel, and then press ENTER.
Right-click HypAlternateResolveToRel, and then click Modify.
In the Value data box, type 1, and then click OK.
On the File menu, click Exit to exit Registry Editor.