Hi,
Please make sure that QC 10 server is running and there is a stable and proper connection to the database server. Depending to the database server integrated to your QC server; verify if you can ping to the DB port number correctly.
Besides, please verify if the URL of QC10 is correct.
You can find the ALM uninstall client utility via the document:
http://support.openview.hp.com/selfsolve/document/KM1400068
Regards,
