Umm, without you knowing what .dll file you deleted or what registry keys you deleted you may be in trouble without the cd
The .dll, you may be able to check out
This small utility
Restoration 2.5.14Save it to a floppy if possibe and run it from there
As far as your reg entry, did you make a backup of your registry beforehand?
Do you know what key you removed?
About your 16 bit colors
Sounds like your Video card drivers are corrupt, may be from you, I'm not sure
Check the makers of your video card for latest drivers and installation instructions
If that get you going, post me back a hijackthis log for help with your spyware
If you let me know what reg entry you removed and possibly it's replaceable, I may be able to write you a script to put it back if it was needed