Is cleaning my system possible after working

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?

Did you mean sensitive? If you are working in some virtual machine such as Windows xp or any other, then you know that you can also quit directly without saving changes you made so that all temporary files, changes in the registry made during your work can be simply dropped and may be forgotten possibly which are not saved in the machine so that next time you can start again with clean slate.

There are many software’s available such as dipfreeze. This helps to remove all the junk files which you have created after you made a restart of your system. Have you heard about virtualbox? This is also good software. When you install this software, it only stores things virtually and not permanently. So, here it does not require to clean you system again and again. This saves a lot of time.

If you are using a computer temporarily, a good way to do this is to create a new entry for you and work from there, and when you have finished working with your computer, log on as the main administrator account and delete the account settings and files of the account you use your sensitive data. That should get rid of everything. Obviously, when working with very sensitive data that must obtain a disk wipe utility to erase all deleted files. Disk wiping and stuff is another issue altogether and is related to the disk hardware and the amount of data is managed.