Costmin is a free browser extension that is supposed to “reduce your costs to the minimum” while you are shopping online.

Please find below a few facts about Costmin we would like you to pay your attention to.

Publisher’s description of Costmin: “Once installed, the add-on will detect online-shopping websites and will offer you special coupons, discounts and sales for the items you searched for in those websites. The offers will pop at the top right corner of your browser and will help you save money and time.” Such deals and coupons may also appear in any place of a webpage, or in a pop-up window with a small note ‘Powered by costmin’, or ‘By costmin’:


 
Even if Costmin is supposed to display similar products with minimum cost, sometimes pop-ups show you a higher price than the one for the original product; or products not relevant to your search:


 
Before Google Chrome adds Costmin to its extensions’ list, it shares the following information with a user:


 
Costmin has an unusual installation folder - C:\Program Data\costmin, also it installs to all user profiles - C:\Users\All Users\costmin.
Program may intentionally change its installation date (which is usually done to confuse a user, and make removal process more difficult). As you can see on a snapshot below, in ‘Programs and Features’ Costmin was allegedly installed on 8/5/2012, and its folder in ProgramData has an actual installation date - 9/2/2014.

Standard removal from Control Panel – Add/remove programs doesn’t help to uninstall Costmin – program continues working until you manually remove it from browsers and from hidden folders on your PC.
If you want to remove Costmin from your PC, please find below step-by-step instructions.

Note. This is a self-help guide. Use it at your own risk. This article is provided "as is" and to be used for information purposes.

1.    Before you start, please make sure you are logged as a system administrator. Also, please save a copy of your important documents/files on external hard drive/cloud storage.

2.    Please close all your browsers (if any).

3.    From your desktop, click on Windows Start button and choose Control Panel option (Windows 8 users: right-click on ‘Windows Start’ icon (by default, it is located in the left bottom corner of your screen), and choose Control Panel from the context menu):

•    Click ‘Programs and Features’ (Windows Vista, 7 and 8)/‘Add or Remove Programs’ (Windows XP),
•    Please find ‘costmin’ -> right click on it and choose ‘Uninstall’.

4.    Please make sure that hidden files in your Windows Explorer are visible: Start –> Control Panel (Appearance and Personalization) –> Folder Options –> ‘View’ tab –> find ‘Hidden files and folders’ and check a box ‘Show hidden files, folders, and drives’.

5.    Follow this path - C:\Users\YOUR_USER_NAME\AppData\Local\Temp (XP users: C:\Documents and Settings\YOUR_USER_NAME\Local Settings\Temp) -> highlight all the files/folders here -> press ‘Shift’+’Delete’ and click ‘Yes’ to completely clean this folder (Note. If you receive messages that some files cannot be removed, just skip the file in question).

6.     Please find the directories below and make sure that all the Costmin traces are removed:
C:\ProgramData\costmin
C:\Users\All Users\costmin
XP users: C:\Documents and Settings\All Users\Application Data\costmin

7.    Now please make sure that your browser is clean:

Mozilla Firefox

•    Click on the Menu button   in the right upper corner of Firefox window (older versions of browser: click on the orange ‘Firefox’ logo in the upper left corner) -> find Add-ons section -> check ‘Extensions’ and ‘Plugins’ tabs, and if you find costmin here, please click on ‘Remove’ button:



•    Restart Firefox.

 Google Chrome

•    Type chrome://extensions in the Chrome address bar and press ‘Enter’;
•    If you see costmin here, please click on a trash can (like shown below) to remove it from Chrome:

 
•    Restart Google Chrome.

Internet Explorer

•    When IE window is opened, press Alt+x keys on your keyboard to open Tools menu -> Manage Add-ons;
•    Open ‘Toolbars and Extensions’ section -> if you have costmin here, highlight it and click on ‘Disable’/‘Delete’ button:

•    Restart Internet Explorer.

8.    Now, please install Ad-Aware to make sure you don’t have any infections on your machine:

•    Click here to download Ad-Aware, and follow installation instructions from Ad-Aware User Guide (‘Installation and Uninstallation’ -> ‘Ad-Aware Install’ section).
•    Perform a full scan of your PC with Ad-Aware (following Ad-Aware User guide: ‘Scanning System’ -> ‘Running a scan’ section).
•    Restart your PC.

9.    If you continue facing issues with Costmin, please remove its traces from your registry. Before you start, please make sure you understand how important this part of your PC is. You cannot restore data from here once you delete something (‘Ctrl+Z’ never works in Registry Editor). And if you delete an incorrect component by mistake, it may damage your OS and make it unusable.

•    To open the Registry, press ‘Win+R’ keys on your keyboard -> in the opened window type regedit and press ‘Enter’.
•    Highlight main registry section called ‘Computer’ -> press Ctrl+F keys on your keyboard -> make sure Keys, Values, Data check-boxes in the ‘Find’ window are checked -> type costmin in the search field and click OK. Search results will highlight a key/value/data that contains Costmin components. If you find the exact match with the name of program you want to remove, right click on the element in question and choose ‘Delete’ from the context menu.
•    Use F3 key to continue the search and to find all the necessary files.
•    Exit the registry editor.
•    Reboot your PC.

Lastly, it is recommended to always keep your antivirus program up-to-date with a real-time protection turned on, and perform weekly full scans to stay protected at all times.