The only purpose of the "Check box" you have mentioned here is to establish Pop Peeper as your WIN 7 Operating Systems default "Email Client", that is all this does (the "check box" is not intended to turn this setting on/off so to speak or to be more precise to "undo" the setting by unchecking). Presumably you want to go back to your former "Email Client" default, this is not accomplished by just unchecking this Pop Peeper "check box". How to change your default "Email Client" is discussed below (the easiest way to accomplish this is to use Pop Peeper to make the change as discussed below and illustrated by the embedded image).
You can set your default "Email Client" using either Pop Peeper or your Win7 OS. (you must have at least one [other] "Email Client" (program) installed on your computer). *
Note: If Pop Peeper is actually your ONLY "Email Client" program then do not proceed any further since you would not want to change this setting from the way you have it since it is best to just leave the setting this way so that "mailto" website links will work.
Using Pop Peeper to switch to another "Email Client" (assuming you have another "Email Client" installed other than Pop Peeper) simply go to where you were before: Under "Tools" > "Options" > "General" and click on the "Email Client" drop-down arrow as you see illustrated in the embedded image below (pointed out by the arrow) and select from the drop-down list the "Email Client" you would like to make your "default" (circled list) and then Click "OK". (to "clear the check mark" as you posted it would be necessary to select an alternate "Email Client" program, which is what is being done here. Unchecking does not provide Pop Peeper with what you want the "default" to be which is why you need to make an alternate selection from the drop-down list to proceed with the change.)
- Select from the list which "Email Client" you prefer to have as your "Default".
Try changing your "default" setting back this way as illustrated above since this is the easiest way to accomplish the switch.
An alternate way to set your default "Email Client" would be via your WIN7 OS. Assuming you have multiple "Email Clients" installed on your computer, only one will be configured to work as the "default" email client. You must use the "Default Programs" option if you want to switch the default email client in Windows 7.
The following steps are the way to do this using the alternate method via the WIN7 OS setting:
1) Click on "Start" and then click the program labeled "Default Programs. (from the list to the right)"
2) Click the option labeled "Set your default programs."
3) Click the email program that you want to set as the default program from within that list of programs.
4) Click the option labeled "Set this program as default."
5) Click the button labeled "OK" to finish setting the selected email program as the default email program.
The example below shows that other than Pop Peeper I have 2 "Email Client" apps to choose from (see arrowed apps), I can then select either one (I have Microsoft Outlook selected) and then click the circled area (Set this program as default) that you see in the image below and follow through by clicking "OK" to make the change:
- Selecting default Email Client via WIN7.
Please report back your progress.