Error 0x80020009 but I'm an administrator

I'm running Win 7 SP1 (64-bit)

I've recently had issues with file corruption in my windows folder that SFC couldn't fix. When replacing one dll file(mf.dll) it was recommended to me that I deregister and re-register it. While the deregistration of it worked fine on trying to re-register it, I was given the 0x80020009. Which I was then told I need to run the cmd in admin mode to make it work. The only problem is I am running it in Admin mode...