can't extract chankast emulator after download

i downloaded it but 7zip says it can't open it as an archive.

i would try redream but...hell no! there's no way i'm PAYING for an emulator. especially when it's just so the graphics look normal.

guess i can try nulldc tille i find a copy of chankast or something (or just stick with nulldc if it works well enough).

edit: apologies... it seems 7zip doesn't extract rar by default when you double click. >.> had to right click and open it that way but got chankast to extract.