Outlook "not installed" error

Hello,

I cannot open Outlook 2003 on my computer. I keep getting the following error:
"Microsoft Office Outlook has not been installed for the current user. Please run setup and install the application." I am the only user on this computer.

Problem started when I downloaded the Windows security updates of July 8, 2008. I restored to a prior date and Outlook ran properly. When I went on vacation, someone used my computer and apparently installed another security update.

When I check the files, it says that Outlook is present, but still won't open. Now, in addition, I cannot open any of the Office Basic 2003 applications.

I have the installation disc, and I need to know, if I uninstall Office 2003 will I lose all of my associated files, such as my Outlook Contact information. If I uninstall and reinstall Office 2003, will it resolve this problem.


I am running Windows XP Professional, version 5.1.2600. Internet Explorer 7.

Thanks for any help you can give. This is my office computer and I need to solve this problem quickly.