All of a sudden the hyperlinks that come up after entering a search into a search engine are malfunctioning. Instead of pulling up the chosen link, a new browser opens and is directed to 0nfind.com and/or an alternative, unrelated site. Links within other websites (other than search engines) still seem to work fine, but the problem persists whether using Internet Explorer or Mozilla Firefox and whether searching via Google or Yahoo. How do I fix this problem?

Your system is infected with spyware.
Time for a clear out and some maintenance.
There are some good tips here: https://www.askmehelpdesk.com/comput...rs-233870.html