Tweak my display?

I have an Acer Aspire 3500. It needed a format when i bought it, so i installed XP Pro on it, with the appropriate video driver from Acer's website. With the brightness settings on the keyboard, all the way up, i went in to the video settings, and tried to brighten it up that way. All i could do was get it to bright. Anyways. After a few weeks, i put Vista on it(please don't flame). I have been using it on my desktop, so i just wasn't "feeling" xp anymore. I didn't install my video driver, b/c it Vista recognized it, and my video card isn't anything special. OK, i don't have any settings to go into to brighten my screen. Acer doesn't have a vista driver for my video card. Is there a program or anything i can download to tweak my screen, or do i need to find the driver? Even with the driver, i cant tweak it how i feel i need to.

 

is their a function + <key> way to do it?

i.e. my laptop is function + f6(down) or f7(up) to adjust brightness.

 

yea, that is what i meant by on the keyboard.