How To Prevent Virus Copy of Shortcut to (1).lnk , (2).lnk,(3).lnk, (4).lnk infecting

recently some of my friends computer OS has infected by the Trojan Family , its ussually make file name Copy of Shortcut (1).lnk , Copy of Shortcut (2).lnk Copy of Shortcut (3).lnk Copy of Shortcut (4).lnk, they donn't know how to prevent its happen so its always infected many times destroying the Operating System, the use of Flash Disk is the largest cause of its happen so may be you can try my tips here
- always check the Flash Disk when its put onn the Computers, are they contains the virus or not usually straight shown  , if does , fastly delete the "link" file.
- check the Flash disk wheter its has folder named RECYCLER , you must delete the folder all of its content, that is the source of virus ,
keep aware of another virus , this step may be can you try to prevent that infecting

Things to khow before choosing Personal Computers (PC)

1. Fast processing : Computer must fast to process programs so it be the best choice to handle every job
2. Cheap : Computers must cheap so its useful and can save money for another reason
3. Quality of the material : is the most important things of all above