paint shop pro...
do a batch process....
its easy, you open a file to resize... click record then just clt-s (iirc) and re-size it!
Next you save that batch process giving it a name.
Then in the menu's there an option to run a batch process... all you do is select the files you want to process... select where the new files are saved to... select the process to use...
AND CLICK START!
or theres a help file you can read
Alex