monitor settings

On my dual boot system with WinXP and SuSE10.0, I have replaced my monitor, as it was losing it's contrast. I already disposed of it. Now connecting newer monitors, I get the message from these monitors, that they are out of range when I want to boot up SuSE10.0 I can boot up WinXP, and also SuSE in safe mode. How do I change my SuSE setting during this safe mode so I can boot up SuSE again? I don't know where I can find the settings for that. Thanks in advance, Frits Wüthrich