error ccSvcHst and 8504,100 with Norton 2013 on XP

Hello,

About a month ago I renewed my subscription for Norton IS but ever since I have problems with it, on my Windows XP desktop. (Everything works fine on my Windows 7 laptop.)

 

When I want to shut down my computer I get an error message that ccSvcHst cannot be closed. And whenever I click on the NIS icon to open Norton IS, I get the error: 8504,100, and the advice to reinstall Norton.

 

I have followed this advice several times, the first time I used the recommended Norton Removal Tool, the second time I removed Norton first with Windows, then the Removal Tool, and then reinstall and update. Whatever I try, the result is the same: at first everything works well again, but after about 1-2 days I start to get the same error messages.  

 

Does anyone know how to fix this? It's driving me crazy...