As soon as Windows is started performance of applications decrease, CPU load is 100% and prl_cc.exe consumes 50-100% of CPU time in Task Manager.
This issue can be caused by Google Quick Search Box enabled for Google Toolbar plug-in of Internet Explorer.
This toolbar can be installed alongside with some third-party applications, e.g. Adobe Reader.
Please disable Google Quick Search Box in Google Toolbar options in Internet Explorer.
1. Open Internet Explorer
2. Select Options for Google Toolbar
3. Uncheck "Enable quick search box to search outside the browser" option.
4. Restart Windows and check the performance now. If the issue persists please contact Parallels Support.