Unable to cast COM Object Type System_

Solution#3:
please try the below solution with the help of local support to fix the issue. Please note that you can only run below scripts as admin on your laptop

Start->Run

Enter “Regsvr32 actxprxy.dll”

Click OK

If the popped up message shows successful, try log in to QC and see. If you still face the same problem,

Please run below script at command prompt:

for %1 in (%windir%\system32\*.dll) do regsvr32 /s %1

for %1 in (%windir%\system32\*.ocx) do regsvr32 /s %1

If both scripts executed successfully you should be able to log in to QC other wise it indicates that there is a problem with .NET framework on your laptop. You have to install it again with the help of local support