Computer Blocked Pop Up

[rsvp]

Twice in the past five days I've had a pop up saying my computer has been blocked and I must call a number for assistance. This has happened on facebook only. Obviously a scam and I haven't clicked on anything. Have run full scan (avast freebie one) and malware (also a freebie one) and nothing has shown up.
To the best of my knowledge the only update I've downloaded is an Adobe flasher player.
Any suggestions in very plain English will be gratefully accepted - thank you

[Buenchico]

Check that there aren't any unwanted extensions installed in your browser. Then clear your browser's history. (Tell us which browser you're using if you need instructions).

[Trishy]

Yes, happened to my computer today on Facebook. I just switched off and ran Ccleaner.

[rsvp]

Hello Buenchico - am using firefox and have no idea how to check anything - not being obtuse but am not good on computers !

[Togo]

RSVP. Are you running w 7. 8. or 10? It will make it easier for someone to post you a walk through.

[rsvp]

Trishy I did that the first time but have got it again today - have also cleared browsing history. Think all will be well as long as I don't open anything on the pop up - gulp, hope so!

[rsvp]

Sorry Togo -windows 10

[Buenchico]

Click the 'hamburger'. (Three lines,top right).
Click 'Add-ons', then 'Extensions'.
If there's anything there which shouldn't be, click 'Remove'.
Close the tab.

Click the 'hamburger'.
Click 'Options', then 'Privacy'.
Click 'Clear all current history' and then 'Clear Now'
Close the tab.

[rsvp]

Thank you Buenchico - have done that - there was nothing to worry about on the first option you gave me and have followed instructions for the second option. I did notice that there was an option on the privacy for firefox to never remember my history - should I click this as well or just delete my browsing history on a regular basis?

[Buenchico]

It's up to you. I've got 'Never Remember History' selected on my own computer though.

[rsvp]

Many thanks Buenchico - maybe logging in each time I close down may drive me to drink so will see how it goes - stay well.

[Buenchico]

PS:
If you still get the pop-up, run Malwarebytes Anti-Malware again but in Windows Safe Mode. (To get into Safe Mode keep poking the F8 key during your PC's initial start-up process until you see the relevant option appear. To get out of it simply restart your computer).

[Baldric]

Those Adobe flasher players can be a blooming nuisance tbh!

[rsvp]

Thank you both - stay well

[Togo]

I sat down to eat RSVP but will post something useful anyway.
Left click little 4 pane window bottom left or press windows key on keyboard.
Left click little cog wheel bottom left , it should say settings if you hover your cursor over it.
Click System and choose Apps and features from the left hand menu.
Select “My Windows(Microsoft) Computer has been blocked” from the list.
Click on Uninstall button to get “My Windows(Microsoft) Computer has been blocked” removed.

This will work with more persistent or serious pop ups that are out there.

[rsvp]

Hope you had good supper Togo - thank you for replying, I went off line earlier so have only just picked up your answer.
Followed the instructions okay until we got to apps in the systems list.........there was nothing like 'my windows has been blocked' - all I got was a long list of what is on my computer. Did try and find it but no luck unfortunately.

[Togo]

You got rid of it I would think RSVP, that is why it isn't showing. Some are a little more persistent and that method may come in useful.

[rsvp]

Thank you Togo - will keep the process you suggested in mind in case I need it again.