This is good software, BUT please learn from this "goof" who spent many unhappy hours troubleshooting once...
You do occasionally need to boot from USB flash memory. Obviously if you boot from Linux on a flash drive, but less obviously, you may need it (as I did...) to boot up your computer with recovery software like Acronis True Image or one of the others.
I also have a lot of diagnostic software on my USB (Memory, CPU & Disk testers for example), which can fail if you disable the autorun feature. So might self-encrypting flash drives, "Radio-on-a-USB-drive" type radios, etc.
I disabled mine using the Microsoft "Fix It" button about 1/3rd down this page:
http://support.microsoft.com/kb/967715 (Note, it is now up to revision 6.3!)
Although there is another approach to be considered, that might be worth thinking about here:
http://blogs.computerworld.com/the_best_way_to_disable_autorun_to_be_protected_from_infected_usb_flash_drives (Although this is from 2009, so their objections might have been address by Microsoft by now?)
There DOES seem to be a difference though between the Microsoft solution of altering the registry and the BitDefender USB Immunizer (which seems to regualry run a program to make sure the registry keys are not enabled again I believe?). So if your computer did get infected somehow, the program might change the registry keys to allow it to infect your USBs that can be infected. The BitDefender USB Immunizer seems more like another program running on your computer - Which some may not want?
What really caught me out though was that for security, I had disabled "boot from USB Devices" in the BIOS - Then forgot that such a setting existed. Several years later, that computer had a major melt-down and I needed to restore it from the Acronis Back-Up image, as Windows would not even boot up So I tried if from the USB Flash drive and of course it would not boot up at all. Eventually while setting the boot-up order in the BIOS, I went through all the setting to see if I could see anything that was causing the problem and came across the BIOS setting disabling boot up from any USB device.
So there are several approaches to this problem, each has it's own benefits and drawbacks though. Just remember what you did, incase you need to change it back again at a later date though...
Incidentally, thank you very much WhiteRabbit for all the friendly welcome on here some time ago, when I posted about games - Your enormous work on the games on here is much appreciated by me!