The user who is using Windows XP home user can follow the below given option for encrypt the file

1. First of all select which you wish to encrypt.

2. Then right-click on the folder and by clicking option will be provided and click Properties from the option provided.

3. By clicking on the properties option again click on the Sharing tab from the list.

4. After selecting check the box which will be as Make this folder private.

5. Click at the option bottom given as Apply and then click the Ok button.