There is a folder on my desktop whose name looks like. Then, you need to find and delete all folders containing FSDUI_Custom.exe and other related files. First end that process tree, by right-clicking on the process and then clicking 'End Process Tree'.

First, open Resource Monitor ( not Performance Monitor) and there (under the CPU section) you'll find FSDUI_Custom.exe running.

I tried a mixture of and answers and it worked for me.

If you find anything to do with it, delete. Also do the same with Norton registry keys - open regedit.exe and click through all the lists until you find something to do with Norton. Manually delete all Norton files on your system by searching for 'Norton' at the C: level in your file system. Optional (Autoruns should be enough to solve the problem, but I would do this just in case): Scroll through the list and uncheck any Norton/Symantec entries that you find. Open the program and wait for it to generate entries for all startup programs (this is a MUCH more comprehensive list than the one in Task Manager).

If you see anything to do with Norton/Symantec, uninstall it.

Go into Control Panel, and check the list of installed applications on your computer.

The link should be enough to answer your question, but in case it becomes broken in the future, here's my version of the answer:

Norton reinstall