Have i just started using ubuntu so sorry if my question seems stupid. I installed ubuntu 12.10 and everything works fine on my laptop except the loud noise and heat problem. Now i asked around and everyone suggested that one of my drivers is not properly set so i checked and found out that under graphics i have Driver = Unknown. Now i tried to look around for a driver to radeon hd 3400 and found one in AMD website downloaded installed then rebooted. My screen went really large and i couldn't see the icons bar to the left. after a 5 hours trying to fix it i purged (Delete?) the driver and ubuntu started working but still driver unknown. Any idea what i have to do to fix this please? thanks.
Try looking in Ubuntu's System Settings, for Additional Drivers/Proprietary drivers, it will probably list the same xorg, fglrx, fglrx-updates that Synaptic finds below, but here it should be a one-click install, even easier :-)
And/or Look in Synaptic for packages called "xserver-xorg-video-ati" (x.org open source) or fglrx or "fglrx-updates" (proprietary). Actually just searching Synaptic for "radeon" should find them. The x.org one works good enough for me, didn't notice any difference with the others, but some people like one or the other (web searches for fglrx & radeon show some opinions)
When I ran Ubuntu live I think it automatically picked the x.org one to use, and Mint does too & works great. Whether or not any of these will fix your heat & noise issues I'm not sure, they could be unrelated to the video. I do remember with my Radeon HD and Ubuntus from 2012 there were some issues, sometimes an older or newer release might work better, may be worth it to try a live usb of 13.04 or 12.04, or Mint, and if one of them runs well check what drivers it's using.
Always easiest to try looking in the software repositories with Synaptic or the "Software Center" programs first before resorting to downloading from websites, there's almost always a ubuntu-specific package someone else has added, or a debian one.
PS Here's a ton of info on Radeon & ubuntu on this ubuntu help page, even stuff about 3d/accelerated drivers that I'll check out myself: https://help.ubuntu.com/community/BinaryDriverHowto/ATI?action=show&redirect=RestrictedDrivers%2FATI