Basically, look for that in the Windows Control Panel > Programs & Features, and remove it from Windows.

See this YouTube video for step-by-step instructions. https://www.youtube.com/watch?v=HgA3pdRIgJI How to remove Search.searchdconvertnow.com from Google Chrome, Mozilla Firefox, Microsoft Edge

the program is not listed on programs and features. Nothing has been installed on the 7th January 2017. The program is not even listed in my download file Any other suggestions?

the program is not listed on programs and features. Nothing has been installed on the 7th January 2017. The program is not even listed in my download file I have run Malware and adw cleaner but it has not removed this searchdconvertnow.com home page hijack Any other suggestions?

The actual program name may be different than what might be expected. And some of that "crap" is bundled with other "free" programs (icon packs and other gimmicks) that might be useful to a user, but the "crap" can't be removed without removing the "host program". (Paying for the "free" with search commissions for re-directing users.)

What's in Programs & Features that you don't recognize? If it has been recently installed, get rid of it.

Did you follow those instructions carefully? Did you check the Properties > Target line of the Firefox desktop shortcut? How about the Homepage setting in Firefox? https://support.mozilla.org/en-US/kb/wrong-home-page-opens-when-i-start-firefox-how-fix