When my computer started acting up while accessing and using search engines, The analysis on the F12 site at boot up that showed a 0146 error . I ran the MS Security Essentialsfor 12 hours (12) to find a virus named "Browser Modification: Win 32/Default Tab". It took 12 hours to do just the C drive. It took another 15 minutes for MS SE to remove it.
Now my computer works much smoother and quicker. I did a web search and came up with suggestions about the error 0146 that said the hard drive was screwed and needed to be replaced and other extreme solutions. Glad I tried the MS SE first.