Hello Awalshga,
If you're not able to uninstall through the normal Control Panel > Programs and Features uninstall process, the next option you can try is the following steps:
***Note: On the workstation, click on Start > Run, type in REGEDIT and click OK to open the Registry Editor. With 'My Computer' highlighted in the upper left-hand corner, click on File > Export, make backup of registry.***
1. In the Registry Editor, browse to the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\ location and search for the Microsoft Dynamics GP 10.0 or GP 2010 install you want to remove.
2. When you find it, you'll see a 'UninstallString' subkey, copy the UninstallString value from the { to the other }.
For example, on my system, I see this:
MsiExec.exe /X{B27D05EB-5C32-ADFA-8106-8E97C7654770}
I would copy this: {B27D05EB-5C32-ADFA-8106-8E97C7654770}
3. Make sure all Dynamics GP applications are closed and then run the following script via Start > Run:
msiexec /x {B27D05EB-5C32-ADFA-8106-8E97C7654770}
This should completely remove that install of Dynamics GP from your system's registry just as good if not better than going through Control Panel > Programs and Features would do.
By doing this, it'll remove all references of Dynamics GP in the Registry, which will also remove it from showing in Programs and Features.
At that point, if successful, you should be able to re-install a new instance of Dynamics GP as needed on the workstation.
If both the uninstall process under Control Panel and using this MSIEXEC /X process fail, then normally the only other option we have is to search through the entire Windows Registry for 'Microsoft Dynamics GP 10.0' and/or 'Microsoft Dynamics GP 2010' and, after exporting a backup of each registry object before deleting it, delete the registry keys until there is no longer any mention of the application. You would also want to delete any folders/files left for Microsoft Dynamics GP as well.
Let us know if you have any questions. If you need further assistance, you may want to open a support case, especially if you don't feel comfortable working around the Windows Registry.
Thank you,