expression
terrible; awful; I don't even want to talk about it
Used in response to a question with どう (how) to express that the situation is so bad it's beyond words. Often dismissive or exasperated.
See also: どうもこうも
「試験どうだった？」「どうもこうもないよ。全然できなかった。」
"How was the exam?" "Don't even ask. I couldn't do anything."
expression
without reason; inevitable; that's just how it is
Used to dismiss a question about why something is the way it is, implying there's no particular reason or it's just fate. Often in response to どうして or なぜ.
「どうして遅刻したの？」「どうもこうもないよ。電車が遅れたんだ。」
"Why were you late?" "There's no 'why' about it. The train was delayed."