When you suddenly find out your mouse wheel make the excel worksheet zoom in and out instead of scrolling it, you can correct it by
- File -> Option -> Advanced -> Zoon On Roll with Intellimouse
https://answers.microsoft.com/en-us/msoffice/forum/msoffice_install-mso_other/mouse-wheel-magnifies-instead-of-scrolls/40644484-e043-446d-bee6-52cbb3d4865a
- File -> Option -> Advanced -> Zoon On Roll with Intellimouse
https://answers.microsoft.com/en-us/msoffice/forum/msoffice_install-mso_other/mouse-wheel-magnifies-instead-of-scrolls/40644484-e043-446d-bee6-52cbb3d4865a