Website looking very odd in latest explorer in Windows 7

I’m using the Modularity template for my website https://www.micheldegroot.com which looks perfect on my Mac’s browser and even okay in Explorer on Windows XP. But on the latest MS Explorer on Vista and Windows 7 my site looks like a mess. Picures are stretched out of proportions and (basic) fonts are getting fat and big. I have noticed that this is the case with several other WordPress sites as well as Joomla sites that I have checked on both systems.

Any thoughts about how to solve this???
Ps. I’m not a php expert, more a trail & error guy…

Michel de Groot