Settings for the regularly installed Screenshot Captor are saved in an .ini file, in directory C:\Users\YOURACCOUNTNAME\Documents\DonationCoder\ScreenshotCaptor, and is called, surprisingly, ScreenshotCaptor.ini
For a portable install it is normally written in the directory where Screenshot Captor is run from. (Unless you wrote in that file where to save the settings, but then you of course would know where that is
)
So any normal backup of your Documents folder, or portable applications folder, should restore your settings (haven't re-done my settings in ages, they just moved with me on several computer replacements).