External Display NOT WORKING - Need to reset flicker rate

I have a Dell Inspiron 1012 running Windows 7 Starter SP1 and I've got it hooked up to my Protron 42" LCD screen with HDMI cable. I changed the flicker rate to 70 Hertz without checking the Proton's maximum flicker rate - yeah, that's really SMART - so now I've got an issue with my external display.

It worked okay for second but then my laptop screen turned black and the external display reads "Signal Out of Range" (duh, the Protron works only up to a 69.8 Hertz flicker rate, which I SHOULD have checked BEFORE changing it, but what's done is done -_-).

Now, when I plug in the HDMI cable, my laptop screen goes to black and the external display still reads that same message. I can't change the flicker rate without seeing the menu on my laptop screen.

Any advice on how to change flicker rate back to 60 Hz?

Hi devenprasad. Thank you for the nice welcome and the advice. Fortunately, I was able to fix the issue myself (before seeing your reply) by doing something REALLY simple. I slightly removed the HDMI cable until the external screen came back on (from the black screen) and I QUICKLY changed the flicker rate on the Intel Graphics Media Accelerator window before the screen turned to black again.

Well, if my explanation made sense to anyone else, it's a "fix" that works - you just have to work fast. I learned my lesson: always check the flicker rate parameters on the external display BEFORE changing the flicker rate! DUHHHH

Thanks again for the advice, devenprasad. Have a nice day!