No, not directly.
Windows XP cannot be upgarded to Windows 7. It has to be done as a clean installation. This means wiping off Windows XP then starting a clean installation of Windows 7.
Create your installation DVD/USB (see here for DVD and here for USB) then restart the computer and boot from the DVD or USB.
During the installation choose CUSTOM (if you choose upgrade it will not work).
Keep in mind that with a clean installation you will lose all files from your hard drive, so be sure to backup any files you wish to keep.