I had to recently uninstall the ask toolbar from a Chrome browser but I didn't have the option to uninstall it or even to disable it. Nice going Google. Give the scumbags of the world all the power they need to embed their garbage in your browser and allow them to make it as impossible as hell to get rid of.
When I tried to uninstall or even disable it I would get the message This extension is managed and cannot be removed or disabled.
Here's what to do : At the top of your browser where you type in web addresses, type in about:extensions or click on the three stacked dark lines in the top right hand corner and in the menu that pops down click on settings.
On the settings page click on the word Extensions in the top left hand corner of that page.
Check developer mode (top right hand corner) you should now see an ID: (a bunch of letters). This would be listed under the extension info. Take note of the ID for the extension you want to delete.
Then you have to navigate to the following folder on your hard drive: C:\Users\(user account)\AppData\Local\Google\Chrome\User Data\Default\Extensions Find the folder with the same id and delete it.
Note you have to set your windows explorer to see hidden files and close Chrome before doing so. Go to Control Panel > Folder Options > click on Show hidden files, folders, and drives also uncheck Hide protected operating system files (Recommended). You will get a warning when you do this so just confirm it. I keep my files system like this all the time but you can just come back here after if you wish and reverse what you just did.
And Now Oct 28 2015:
Just spent some time trying to get rid of another one of these pieces of crap and the simple procedure listed above didn't work this time. The malware was a piece of garbage called EasyCalendar. After following my own procedure I couldn't get rid of it.
I found this article that made two suggestions that I didn't try before. One was to search in the registration database and delete any references to that particular extension. In the search bar or run on the start menu type in regedit and hit enter.
Then when the editor opens click on Edit and then Find, copy and paste in the name of the extension ID or type it in and then click on the Find Next button. Make sure all options are checked in that box before searching.
Right-click and delete the key when found.
Then, and this is new to me, there are two folders you are supposed to delete. Again you'll probably need to see hidden files. Go to the following folder on your hard drive C:\Windows\system32\GroupPolicy and delete the the Machine and User folders.
One other thing I did. I have the Windows search disabled on my system (and I can't get it back, an issue for another time), anyway I use the Everything search - www.voidtools.com/
It's more like the Windows Xp search which I liked and not like the Windows 7 search which I can't stand. So I used this to search for all instances of the extension ID and deleted every file it found.
Here's a more detailed link to help with this issue.