Have (or did) you another Anti-Virus installed in this system, if so what was it and how did you get rid of it ?
Given the other topic you created (possibly related to this, should probably be in the same topic) it could be that the above is the issue.
Shields only scan if they are monitoring activity, email or IM application and then only oif they are supported IM applications and you don't give any information.
What is your email program and/or are you using web based email ?
Are you using an IM and if so what is it ?
The Behaviour Shield has nothing to monitor in 64bit OSes currently it is there, but there are no specific rules for 64bit.