Upgrading instance to PL 10 on Web Tools - causes Unhandled Exception Error

Question

Help - trying to do an upgrade to an existing PL 08 Web Tools live site on a hosted Web Server.
When I run the installer and as to do an upgrade to an existing instance, I hit the finish (or really start) button and I get this unhandled exception error
Any ideas???? Thanks
See the end of this message for details on invoking
just-in-time (JIT) debugging instead of this dialog box.
Exception Text **************
System.IO.FileLoadException: Could not load file or assembly 'NetPoint.API, Version=2007.0.630.10, Culture=neutral, PublicKeyToken=d935c97cd97f6431' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)
File name: 'NetPoint.API, Version=2007.0.630.10, Culture=neutral, PublicKeyToken=d935c97cd97f6431'
   at Installer.Workers.BackupDBWorker.OnDoWork(DoWorkEventArgs e)
   at System.ComponentModel.BackgroundWorker.WorkerThreadStart(Object argument)
WRN: Assembly binding logging is turned OFF.
To enable assembly bind failure logging, set the registry value [HKLM\Software\Microsoft\Fusion!EnableLog] (DWORD) to 1.
Note: There is some performance penalty associated with assembly bind failure logging.
To turn this feature off, remove the registry value [HKLM\Software\Microsoft\Fusion!EnableLog].
Loaded Assemblies **************
mscorlib
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.1433 (REDBITS.050727-1400)
    CodeBase: file:///C:/WINDOWS/Microsoft.NET/Framework/v2.0.50727/mscorlib.dll
Installer
    Assembly Version: 2007.0.630.10
    Win32 Version: 2007.0.630.10
    CodeBase: file:///C:/Program%20Files/SAP/SAP%20Business%20One%20Web%20Tools/Installer/Installer.exe
System.Windows.Forms
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.1433 (REDBITS.050727-1400)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Windows.Forms/2.0.0.0__b77a5c561934e089/System.Windows.Forms.dll
System
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.1433 (REDBITS.050727-1400)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System/2.0.0.0__b77a5c561934e089/System.dll
System.Drawing
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.1433 (REDBITS.050727-1400)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Drawing/2.0.0.0__b03f5f7f11d50a3a/System.Drawing.dll
System.Xml
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.1433 (REDBITS.050727-1400)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Xml/2.0.0.0__b77a5c561934e089/System.Xml.dll
System.ServiceProcess
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.1433 (REDBITS.050727-1400)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.ServiceProcess/2.0.0.0__b03f5f7f11d50a3a/System.ServiceProcess.dll
Accessibility
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.1433 (REDBITS.050727-1400)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/Accessibility/2.0.0.0__b03f5f7f11d50a3a/Accessibility.dll
System.Data
    Assembly Version: 2.0.0.0
    Win32 Version: 2.0.50727.1433 (REDBITS.050727-1400)
    CodeBase: file:///C:/WINDOWS/assembly/GAC_32/System.Data/2.0.0.0__b77a5c561934e089/System.Data.dll
JIT Debugging **************
To enable just-in-time (JIT) debugging, the .config file for this
application or computer (machine.config) must have the
jitDebugging value set in the system.windows.forms section.
The application must also be compiled with debugging
enabled.
For example:
<configuration>
    <system.windows.forms jitDebugging="true" />
</configuration>
When JIT debugging is enabled, any unhandled exception
will be sent to the JIT debugger registered on the computer
rather than be handled by this dialog box.

Answer 1

In all likelihood, the dlls are not being replaced because they are in use, and the installer is trying to load the old version which did not get replaced.
You can try manually turning off the synch service and messaging service. Also, make sure the synch manager is not running.
Then uninstall. 
Check the installer and synchmanager directoriesw in your C:\Program Files\SAP\SAP Business One Web Tools folder (or where ever it was installed) to make sure all .dll and .exe files have been removed.  If not, something is probably still open an using them.
If the dll and exes have been cleared out. Then run the installer (the installer that installs the installer )
check the version of the files that were installed in synchmanager and installer directories. 
they should be 2007.0.630.10.