what do i need to do in order to get the right thing?
Completely delete HL2 from your computer. Don’t just uninstall it from Steam but also go to the Steam folder and delete the HL2 folder (should be in c:\Program Files\Steam\steamapps<account name>\Half-Life 2), then re-download it from Steam.
why do that? It obviously looks like it’s stuck on mat_fullbright 1
delete the cfg folder in hl2, that’s what I would do, but if that fails, do what Maxey suggested
already done that did’nt help 
, anyway I can get the unupdated version of half life 2 back or something?
yeah open tpb and enter half life 2 its that easy
OIC wat u did ther
Try cleaning your registry: delete HKCU\Software\Valve, HKLM\Software\Valve; you could also try to manually delete the HL2 folder and later verify the game’s files. If that won’t work the likely issue is the graphics card’s drivers, you could try Driver Sweeper if you want a clean install. Other than that… maybe a DirectX issue.
if you haven’t already, update your drivers
MAGNET! Do like others said… Un-install then delete… then… re-install… if that doesnt work, make sure your drivers you updated were the correct ones…
You have a Geforce 6200, your only hope is the old version of HL2, I run it nonsteam on my EEE PC netbook, the new version doesn’t even boot up.
:fffuuu: yep, latest Valve updates via Steam really screwed us 6200 owners. Given it barely meets the minimum graphics requirements of current HL2 games, I fully expect Valve to totally screw us over when they release (if ever) EP3 and it’s inevitable Source engine upgrade. We’re doomed, Valve hates us, life sucks. 
Valve just gave up on their low system requirements agenda, but at least their old versions still meet our old PC’s requirements 