Windows Help

Let’s start with the basics. Your best line of defense is making sure you’re only using Windows PC as a Standard User. You should never use an administrator account to surf the web, check email, etc. It’s estimated that 94% of all malware infections can be mitigated just by using a Standard User account (https://www.computerworld.com/article/3173246/94-of-microsoft-vulnerabilities-can-be-easily-mitigated.html).

Microsoft has an excellent post and video detailing how to set up a Standard User account:
https://support.microsoft.com/en-us/help/4026923/windows-10-create-a-local-user-or-administrator-account

If you already have all your stuff in your current account and don’t want to switch, you can downgrade your rights by creating another administrator account with a password, logging into it, and changing your current account to a Standard User. Don’t forget the password of the new user account or you’ll lock yourself out of being able to install new software and creating other accounts.

If you think you might be infected, the best course of action is to make sure you have two backup copies of all your data, and reinstall your operating system (Windows/Mac).

For Windows there are three steps you can try:
Reset Windows 10
Reinstall Windows 10 Using Installation Media
Clean Install of Windows 10 Using Installation Media
Details of what happens during each process can be found here:
https://support.microsoft.com/en-us/help/4000735/windows-10-reinstall

There are tools that can help clean up a PC, but I wouldn’t use them to do anything more than scan any data you may try to salvage. If you are able to recover data from an infected machine, I highly recommend you scan it with a few different tools to prevent infection of a new or reimaged/reinstalled machine.

Malware/Virus Removal Tools

Malwarebytes
http://www.malwarebytes.org/mwb-download/

Malwarebytes Adware Removal Tool
https://downloads.malwarebytes.com/file/adwcleaner

Emsisoft Emergency Kit
https://www.emsisoft.com/en/software/eek/

Hitman Pro
https://www.hitmanpro.com/en-us.aspx

Panda Cloud Cleaner
http://pandacloudcleaner.pandasecurity.com/

Kaspersky Virus Removal Tool
http://www.kaspersky.com/antivirus-removal-tool?form=1

G Data Cleanup
https://secure.gd/dl-uscleanup

Eset Online Scanner
http://www.eset.com/us/online-scanner/

Eset Rogue Application Remover
https://support.eset.com/en/kb3035-how-do-i-use-the-eset-rogue-application-remover-erar

Adlice RogueKiller x64
http://www.adlice.com/software/roguekiller/#download

Avira PC Cleaner
install.avira-update.com/package/pccleanerwebloader/win32/en/avira_pc_cleaner_en.exe

Sophos Virus Removal Tool
http://www.sophos.com/en-us/products/free-tools/virus-removal-tool/download-now.aspx

F-Secure Online Scanner
https://www.f-secure.com/en_US/web/home_us/online-scanner

Trend Micro Housecall
http://housecall.trendmicro.com/

Vipre Rescue
https://www.vipreantivirus.com/vipre-rescue-virus-removal-tool.aspx

Dr.Web CureIt!
https://free.drweb.com/download+cureit+free/

Microsoft Malicious Software Removal Tool
https://www.microsoft.com/en-us/download/details.aspx?id=9905

McAfee Stinger
http://www.mcafee.com/us/downloads/free-tools/stinger.aspx

Norton Power Eraser
https://support.norton.com/sp/en/hk/threat-removal-solutions/current/solutions/kb20100824120155EN?entsrc=redirect_pubweb&inid=hho_supp_htm_trs-cur-retail-topfaq-01-kb20100824120155EN

Anti-Rootkit:

Kaspersky TDSSKiller
http://media.kaspersky.com/utilities/VirusUtilities/EN/tdsskiller.exe

Malwarebytes Anti-rootkit
https://www.malwarebytes.org/antirootkit/