HELP PLZ! My HTC dialer has dissapeared

[geno101]

...what have i done? I dont kno exactly what caused this, but i can say that I installed the Rhodium Hidden Settings app, and shortly after that, i changed some values under HKCU\Control Panel\Sound Categories to fix this problem with in-call volume i'm having.

After doing that, i pressed the talk key and all of my call history was jumbled up on top of each other and i couldn't read any of it, but the HTC dialer was still there.. so i soft reset and when it came back on, i'm left with what i'm guessing is the WM default dialer... I called my phone from another phone and even the screen to show incoming calls is different. No sliding answer or ignore key. Just two soft keys. Im assuming this means the HTC phone software itself is gone.. I dont know how to restore this to what its supposed to be..

The only other problem i'm having since then is Installing a CAB for framework 3.5 that i previously could install but now cant.. It tells me "Instalation error. Stop all applications and processes, maximize available storage space, and run installation again. Support info:2."

Please help me, as i am trying to avoid a hard reset.