Hardware wiikey update 1.2 cant open TAR help plz

[Twiggy12]

im trying to update my wiikey so that it blocks ALL updates because i want to play animal crossing but have to update, normally id have no problems but for some reason, when i download the TAR file off the website i try to open it and it says...."the file is either an unknown formot or damaged

now i can open .TAR files normally (i have winRAR) but when i open it it comes up with wk2EurV1.2.tar.bz2

and it should only be .tar so why wont it work, and if anyone could you give me the direct file in .rar or .zip