OK, now I am having a problem on my XP3 computer! In addition to the installation error reported on my Win7 computer.
Today I had a stop error requiring computer restart. Now I am getting "Real-time protection is disabled," and the problem cannot be fixed. See screenshot. I also had the invalid license warning.
???? Seems like a lot of problems with BD IS 2011. The 2010 trial product was working fine, nothing but problems since I bought IS 2011. 
