Hi Gary,
This is Mike from the Norton Authorized Support Team.
What Norton product and version are you using? Please reply back and let me know.
If a scan is stooping prematurely it can indicate a deep infection on your system or it can be a problem with your installation of Norton. The first thing you should do is to try manually running LiveUpdate by going to 'Start"->"Run" and type in "luall.exe" (without the qutoes). Then follow the prompts to check for and install any available updates.
After the updates have been applied, restart your computer into Windows Safe Mode, launch your Norton product and complete a "Full System Scan."
Please follow these steps to properly uninstall and reinstall Norton. Please make note of your activation key and registration information.
1. Click on the following link to download the Norton Removal Tool:
Norton Removal Tool and Instructions
2. After you run the tool, please restart your computer. Then log in to Windows again and run the removal tool again. Restart your computer after it is finished running the second time as well.
3. Make sure that your internet connection is working properly, and then reinstall your Norton product. Towards the end of the installation process, the LiveUpdate feature will automatically run and download and install updates to both the program files and definition files.
4. After you have reinstalled Norton and LiveUpdate has run, complete a Full System Scan.
Thank you,
Mike
Michael York
Norton Authorized Support Team
Symantec Corporation
http://service.symantec.com/priority