If your data files on your hard disk are taking consuming too much of your hard disk space, then you can compress them to free up the hard disk space. In Windows XP, you can compress a file through the command line or by changing the file properties from the Windows GUI. Here is how :
Using Windows GUI
To compress a file or folder, right click on a file or folder and select Properties. Select the General tab, if it is not already selected. Then click on the Advanced button as shown,
This would open another window title Advanced Attributes. In this window, check the checkbox labeled Compress contents to save disk space. Then click OK to save the settings.
If you compress a folder, then any files you copy or move to that folder in the future will be automatically compressed.
Using command line
To compress files or folders using the command line is easy. Press Windows logo key + R to bring up the Run dialog. In the Run dialog, type cmd to open the command prompt window. In the command prompt, give the following command :
This would compress all the files in the folder c:data. If later you want to uncompress the files, then you can give this command :