I am a dummy on the PC which is why I sought help.
As far as I can tell, you access the router via your web browser, IE, firefox or whatever, by typing in the address of the router instead of the http bit - something like 192.168.1.1 and hitting enter.
This should display some router settings - if 192 etc. does not work refer to the manual for the router to get the address.
Then work through the menus to the advanced one where a setting for the MTU will be displayed. You may need a password to get in - on my router admin in both boxes did the trick.
Hope someone else can give fuller help to you.
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