For my work, I use Windows 7 Professional which is installed in my computer for sensitive data on projects, sales, etc. I use various types of programs like MS word and Excel, Adobe Photoshop and Flash, AutoCAD, statistical analysis software, and some others. After work, save all files in a pen drive and eliminate the "Attachment" files created by programs. I also use a program to permanently delete files. However, I cannot really be sure that my computer has been cleaned, and there are no traces of my work. What if I forget a file attachment? This has become a major concern for me, because I suspect that someone in the office is able to access my machine. So is there a reliable way to really clean my PC after having worked with it, also in a way so that there would be no opportunity to read the deleted files, and special programs. Someone suggested installing a virtual XP machine and working within it, but what changes then?