Did you download directly to the healthy drive or did you copy-paste it ?
Right click wow.exe, go to properties, compatibility, check run this program as administrator, apply and click ok.
Right click wow.exe again and click troubleshoot compatibility, use whatever settings it recommends and report back.
If that doesn't work, go to your WTF folder, open config with notepad and replace everything with this
Code:
SET locale "enUS"
SET realmList "logon.warmane.com"
SET hwDetect "0"
SET gxResolution "1366x768"
SET gxRefresh "60"
SET gxMultisampleQuality "0.000000"
SET gxFixLag "0"
SET videoOptionsVersion "3"
SET movie "0"
SET Gamma "1.000000"
SET readTOS "1"
SET readEULA "1"
SET showToolsUI "1"
SET Sound_OutputDriverName "System Default"
SET Sound_MusicVolume "1"
SET Sound_AmbienceVolume "1"
SET farclip "1277"
SET specular "1"
SET groundEffectDist "70"
SET environmentDetail "1.5"
SET mouseSpeed "1.1000000238419"
SET accounttype "BC"
SET checkAddonVersion "0"
SET gameTip "58"
SET Sound_EnableErrorSpeech "0"
SET Sound_SFXVolume "0.30000001192093"
SET Sound_MasterVolume "0.69999998807907"
SET DesktopGamma "1"
SET particleDensity "1"
SET weatherDensity "1"
SET textureFilteringMode "5"
SET shadowLevel "0"
SET Sound_EnableSoftwareHRTF "1"
SET Sound_VoiceChatInputDriverName "System Default"
SET Sound_VoiceChatOutputDriverName "System Default"
SET timingTestError "0"
SET accountName ""
SET componentTextureLevel "9"
SET gxWindow "1"
SET gxMaximize "1"
SET lastCharacterIndex "6"
SET Sound_ZoneMusicNoDelay "1"
SET realmName "Lordaeron"
SET ffxGlow "0"
SET windowResizeLock "1"
SET Sound_EnableSoundWhenGameIsInBG "1"
SET Sound_EnableAmbience "0"
SET Sound_EnableMusic "0"