for example if i install winrar
and uninstall it
if some expert will look good he can see there was winrar installed on the OS
how can i erase software in way no1 will know that this kind of software was installed on the OS
without formatting the entire OS
This is not easy. There will be always some traces left - depending on the program. Your best option is to use the advanced option of the Revo Uninstaller. That removes most registry entries and files connected to the program.
Note that the freeware version will do all x86 programs but for the x64 programs you need to Pro version.
and one more thing
i need that external dvd that was connected could not be found
there was some program that remove all usb traces.
so if expert looks and check if usb drives were connected to pc he can find some and than suspect
how can i remove all windows usb drives traces from the OS?
thanks for that info
i did it with revo uninstaller advanced clean but before he start the uninstallation he make full registry backup
so if someone will restore this reg backup using revo he could see those programs were erased not?
If you really want to have your computer completely clean then the only way to do it is to format the hard drive and start all over from scratch, or better yet just replace the hard drive with a new one, and reinstall Windows.
Almost everything you do leaves some trace behind someplace, especially if you have an existing backup made before removing the material.
A recovery program will even see all the recently deleted files.
This is why everyone should make system image files at regular intervals.
If you get a virus or install software that messes up your computer you can overwrite the whole drive with the image file and it will be back just the way it was before.