Installed programs on Vista appear much larger than XP

I have 2 notebooks, one with Home Premium Vista 32bit and the other with XP. When I install the same program on both operating systems why does the program on Vista appear installed 3 times the size than on XP?

Lois

Check your DPI setting
http://www.sevenforums.com/tutorials/443-dpi-display-size-settings-change.html

Vista and for Seven

Richard,

Sorry, I haven't explained very well... It's not the appearance of the program, it's when I go into Control Panel - Programs - Programs and Features and see the size of the program installed on the Vista (in otherwords, the amount of space it takes up on the hard drive) compared to when the same program is installed on XP it takes up much less space.