Full system scan

I need help, step to step to do full scan

I open  internet explorer , open internet security 2010 I go to  application rating insight  I click standard trust and show  85 trusted needs 15 % to be scanned, then I go to the main Norton window I click Scan and I click the full scan he star the scan but after an how he scan more than 100,000 files and don't finish the scan then I have to stop the scan because 15% is not that amount of files.

Please help me don't send me to the Norton page because no explain any thing but what are the different scans.

 

                                                                                                   Thank you jucoe