When using a shared system you may want to password protect a file. Even on your personal computers you may have saved data that you may not want anyone else to access. Today there are software and programs available which help you do just that.
You could use a program called cryptext. This program allows the user to encrypt and so that no one can access it without the password. IT is a fairly easy program to use. All you need to do after installing the program is to right click on the file and choose the encrypt option It will ask you to set a password and your file will become safe as soon as you do so. When you need to decrypt a file, you follow the same step and choose the decrypt option and you will be able to access the file. The best thing about it is that it is absolutely free and can be downloaded from znet.com/downloads by typing the name as it will take you to the download link.
Another good program is PGP. It is also free and is accessible at Pretty Good Protection International. An interesting and unorthodox way to protect files is to change the header and the extension of a file. It basically involves changing the format of the file. For example if you want to encrypt a bitmap file you can open it in a word pad and remove the first two characters that say BM (the header). You can change the extension as well but while saving the file you may put BM at the start to remind you which program to use for opening the file later. In this way no paint program would recognize the file. This is a clever way of corrupting files which can be restored only by you.