You should know that Smart Protection 2012 is a malware tool trying to imitate a good spyware protection system.
There are several signs that your computer has been infected with Smart Protection 2012. The first one being some system alert saying your PC has been infected with lots, and lots of important viruses. Whenever you click on such alert, or if you do accept it, then you will start an application looking similar to any real antispyware application. It will then run a fake virus scan, and will display many false positives, many of which are designed to look very serious. Another great sign of infection is that the execution of most.exe files will simply not work, and you will have a very restricted Internet access. This prevents users from easily installing removal tools or antivirus software.
Take into account that Smart Protection 2012 is a scam program. It will try to convince you to buy it so you will believe to be protected from all those false positive programs. Do not be intimidated. Like many other scams, Smart Protection is easily identified as being malware with a simple internet search. If an unknown and unauthorized program asks for any money for protection, or makes threats to intimidate into purchasing, it is most likely attempting to steal money or personal information.
So you can become infected in various ways, including the following: video codecs, email attachments, toolbars, unsecured networks, online virus scans, pirated files.
If you are careful when using the Internet and with your emails, then such behavious will prevent tons of infections. To protect your computer from such malware is simply not enough. To fully protect your computer system, you will need scheduled scans that are fully updated and at a professional level.
Use a removal guide or seek the help of some professional the moment you become aware you are infected with Smart Protection 2012. Consider this application as quite dangerous. It will prevent you from removing it, from accessing the Internet, or even from installing new files. It is not something quite easy to remove this application so you will need some help. You won't really be able to delete this malware by yourself even if you try to.
As much as I like free antivirus clients, I do not recommend them as a first line defence. The reason for this is they often lack either the latest virus definitions to remove virus threats or that do not provide live up front protection. Clients that do not provide up front protection do nothing at all to stop a virus from infecting your computer. It's only after the system is infected that they kick in and remove the threat.
Check this website how to remove smart protection for additional info about Smart Protection removal, and this page remove virus about virus removal guides.