Security Shield has gone through dozens of mutations over the last year. This virus does not seem to be dying off. Users have a hard time removing this virus than others but the method is still the same. You should focus on stopping this malware from running. After this is done the remaining process is easy.
Preventing this malware from running is going to be hard. Put your computer in safe mode with networking so you can install an antivirus program. Update the program and start a full scan. This may not work in each case but it often works. A good free client to use is Malwarebytes. You can download the software on the internet with ease.
Like most other malware clients this threat does not do a huge amount of damage. It will block programs from running. It will also make installing software very hard. A lot of the times Internet Explorer will be easy to run still. The malware still might re-direct the things you search for online.
At this point you'll need to try to start your PC in safe mode with networking to install an antivirus software to remove the virus. At this point use it to full scan the computer. There are many clients that will work in safe mode, most will not.
You can use the browsing option to search the paths in Security Shield and delete the file if you need to. This is the fastest way and the quickest to erase it. View the above sites we mentioned for the latest folder and file paths. They change all the time so looking there is your best bet. Doing a System Restore seems to work very well for some people. This option will undo all the latest changes including installing the virus.
Getting a computer infection is never easy. Not for people who use their computer every day. I love free antivirus options but they don't have all the protection that's necessary to stay safe. Most free protective programs have a paid version as well. The paid programs work the best. You'll get live protection up front. There will also be updates and real time support for you. It's better to invest the 40 dollars per year to protect your computer than use the free antivirus.
Make sure you are able to keep your computer safe as you browse the net. The safer you are the less you have to worry about your personal information online.
Here's a video tutorial about how to remove security shield here.