Under Services there are 7 SharePoint services (this number can vary depending of your settings).
Please ensure that the Administration adn timer services are runnning and the logon infor is correct.
Also please check the documentation and be sure that you have the right permissions to perform the installation.
The doc says the following
Quest Web Parts for SharePoint requires administration rights on the SharePoint server during installation. The user who is running the installer needs to be a domain user with local administrative rights.
If your SQL Server is located on a different machine than the SharePoint server, please ensure that you login as a domain user that has permission to write to the SharePoint configuration and content databases in the SQL Server.