okay, maybe it's been asked but i couldn't find any solution,
i've never used Ubuntu, i am mostly windows user.

finally i installed it. of course i used something else option
and then installed it on another drive as it didn't ask me install along side widnows,
or am not sure if it asked.

but point is, after installing it never appeared in Selection to go into ubuntu, it directly goes into windows.

also, then i deleted all those drives where i installed ubuntu on, and then again formatted them so that i can do it all over again.

but i don't know what's wrong.