Something potentially libelous

Or maybe it's just me being stupid.
    While attempting to conform to CreateSpace's strict demands re converting Docx to PDF I thought I'd download their PDF and fix it the easy way before re-uploading it again. My first problem is that I don't have the software to edit PDF's. I then downloaded Wondershare PDF editing software - which didn't work.
    I then uninstalled it - or so I thought. When I rebooted, up it popped asking me if I'd allow it to make changes to my pc. I clicked no and tried to remove it manually. I found every instance of it on my hard drive and deleted them. It didn't work. 
    Now I'm not claiming this software to be malware for fear of getting sued, but try as I might I could not get rid of it and looking through several dozen forums only showed me that thousands had tried, and failed before me.
    I finally went through ctrl/alt/del then Processes then going to containing folder and disabling it. It isn't popping up any more but it's still there and short of reformatting, which I'm not sure will work, it's still there lurking and refusing to go away.
    I even tried my old favourite, Ccleaner which will get rid of everything - except apparently Wondershare.
    I don't like messing with the registry after several earlier disastrous attempts, but if someone knows how to eradicate this pest I'd be your slave forever.