Windows zooms in to the max unexpectedly

[avic2k]

Hi, I'm experiencing odd zooming on windows 10.
every once in a while windows will zoom to the maximum of the current screen I'm in. rather its on a web page or even on the desktop, it happens during work but I could also be on a brake, come back and all the icons are at max size.
this is similar to scrolling the mouse wheel while holding ctrl so I initially thought my mouse was broken but replacing it and updating the drivers didn't fix the issue. thought maybe its a virus but did a scan and nothing found. I also did a google search but all the discussions were about touch pad and touch screen and this is a standard desktop pc, no touch anywhere. whats going on?
its not the mouse and and its not a specific software, is it windows itself? how no one on the web had this issue as well?..
Thanks in advance,

 

[avic2k]

Hi All, thanks for all you comments!
I might have figured it out, thought its too soon to celebrate.
I have a microsoft natural keyboard 4000 that has a quick scroll knob in the center, I never used it so I forgot about it but disabling its feature through the microsoft keyboard control panel seems to have stopped it - so hopefully its the keyboard that was causing this behavior.
not sure what could have caused it to fault like that..