Trouble between NIS 2009 and Adobe Flash Player?

Hi everybody! Today I had a trouble and, in fact, was afraid of a strange behaviour of my PC. Windows 7 (64 bits) started and appeared the Adobe Flash Player advertising that was a new version to install. Instantly, the operating system "froze" and didn't let me start the Task Manager nor NIS; I had to reset forcing the system; again, appeared the installer and PC crashed again, and didn't let me use none of my applications, including NIS. 

 

After a third reboot and a new appearance of Adobe Installer, I simply marked the option to not install it, so te PC worked normally...

 

The question: how can I install Adobe Flash Player if NIS crash Windows believing that it's a virus??