.png

i have a lot of good looking icons but they are in png format.i want to set them as icons for folders in my harddisk.but xp only allows .ico files to be set as icons. how do i convert .png to .ico. also i do not want to object dock/style xp/.........etc coz i am low on ram. i simply want to...

i installed crystal xp recently... then i downloded some icon packs from its site.. it contains icons in .png & .ico formats... how should i apply these new icons??