So earlier today my mom spent most of her morning on the computer shopping for swimsuits and shoes
(an fyi about my mom: she is terrible with technology and is very gullible when it comes to internet ads so she tends to mistakenly click on ads that end up infecting our computer; meanwhile my dad refuses to get a good antivirus software so we are stucking with a subscription-paid Norton antivirus that doesnt detect this stuff)
now when I got on i noticed the default browser had changed to something like speedsearch.org (some stupid third-party search engine scam crap) and that whenever i browsed on pages, like, literally just on the forums or on any other website, this crap shows up on my screen all the time:
<image removed because apparently youtube is piracy>

ive already downloaded and run malwarebytes but it didnt help. however i did manage to fix my chrome settings and remove several adware extensions that had parasited their way into my browser. i also managed to remove that stupid speedsearch engine. now all thats left is getting rid of this netcrawl adware crap.
also the one thing I can NOT do is uninstall and reinstall chrome. this is my family's desktop computer and my dad already doesnt like chrome (it took months of me persuading him to stop using internet explorer) so i'm already on thin ice. i've tried finding a way to save his bookmarks and pages but i have been unsuccessful. if i try to reinstall chrome and he loses all his bookmarks and favorites tab pages he will flip his lid and chances are he won't allow me to use the computer for a long time.
also considering my parents are extremely conservative, they have netnanny installed on the desktop too so every time these ads come up i have to click out of the stupid netnanny popups 500 times warning me that every webpage research
any help guys?