Getting somewhat into guesswork territory, here, but this is what I'd try.
Select the uninstall tool linked above, right click, "Run as>administrator"
Reboot.
Disable Spyware Doctor.
Select the IE icon, go to the adobe
here and download the installation file.
Close IE.
Right click that file, select "run as> administrator" and let it install.
My guess is that an element of SD maybe uses IE, thus locking it, or is in some other way blocking its installation.
It shouldn't really need admin rights to install, so up to you if you want to skip that aspect of the instructions.
See how it goes. Good luck.