After the installation you have to setup your QTP:
- in Quality Center Connection of QTP create the connection to your QC server (use your login/password/projectname/serveraddress),
- in Tools/Options choose Run section and select "Alow other HP products to run test and components" option.
QC10 provide end to end test management web repository solution with test process guidance. It also provide version control and shared repository. It can integrate with QTP or 3rd party tool. It can be manipulate by its OTA API. In terms of automation (as like manual), test can be schedule , maintain, run , enhance,lagged for defect, maintain test coverage, update traceability and share/update from QC by any team member(with correct permissions).
if you are stuck with QC then open the task manager and kill all iexplore.exe and delete cookie etc. After this launch QC again and click on the Add-ins Page link as said by FredMan and install Add-In.
if it doesn't please restart the system and do the same steps.