Corrupted Windows Installer Database

My system has the following software installed:
1. Windows XP SP2
2. MS-OFFICE XP
3. MS OFFICE 2000 The problem I face is that when I try to open the Visual Basic application, a screen prompts me to locate `Data1.msi."
A prompt comes up with the Title "Windows Installer" and the problem is: "The feature you are trying to use is on a network resource that is unavailable.
Click ok to try again or enter an alternate path to a folder containing the installation package `DATA1.MSI' in the box below."
I have no MS-Office 2000 installation CD but I have Office XP.
When I try to uninstall Visual Basic, it gives an error number: "setup error 544. Setup is unable to open the data file `c:program files\microsoft visual studio\commmon\setup\1033\setup.stf'; run setup again from where you originally ran it."
When I click ok, the system again displays the following message: "Setup is unable to open the data file `c:program files\microsoft visual studio\common\setup\1033\setup.stf'; run setup again from where you originally ran it."
When I click ok, it says "cannot be completed". How can I get back my system to its original state?
I have checked my system with Registry mechanic 4.5, RegSupreme 1.3 and advanced system optimiser. But the problem persists. Please suggest a solution.
Vishnu Vikram

These types of troubles are mainly due to problems with the Windows Installer database, which might get damaged due to registry corruption.
In such a scenario, you will not be allowed to reinstall or uninstall the affected applications.
There is a tool known as "Installer Cleanup Utility" which is typically meant for situations like this.
You can download it from http://support.microsoft.com/?scid=kb;en-us;290301
Please install and start the tool. You will get a list of all the applications installed using Windows Installer.
Using this tool you can select the problem-causing applications and remove them.
Removing these applications from this tool will remove all the entries related to the selected applications from the registry so that you can reinstall the application again.
When reinstalling, you need to reinstall the application into the same directory path as it was installed before.
In your case you will have to first remove Office 2000 using the tool and then try reinstalling Visual Basic 6.
If the repair fails, please remove VB6 using the tool and reinstall it into the same directory as before.
Another way to solve this problem is by using System Restore.
By using this method you can switch back your system to a previous date, a date before this problem cropped up.
This is made possible because Windows XP takes a snapshot of your system periodically or whenever a significant system events happens, such as an application/driver installation.
You can access the `system restore' wizard by going to Start -{gt} Programes -{gt} Accessories -{gt} System Tools -{gt} System Restore.
System Restore basically works like the `Undo' command in Microsoft Word.
You will be presented with a calendar and you can select a date when the system was running stable and restore the system to that date.
The point to note is you will lose all system change made to your system since the selected date.
For the detailed procedure for restoring, please look up http://support.microsoft.com/default.aspx?scid=kb;EN-US;Q306084
For more details on System Restore, please visit http://www.microsoft.com/windowsxp/using/helpandsupport/ getstarted/ballew_03may19.mspx