All Windows versions below Windows 10 will come with MS Paint by default. Although quite basic as photo editing tools go, it can still resize pictures rather easily. To do so, follow these steps:
- Open the image by either right-clicking on it and selecting Open With, or clicking File, then Open on the Paint top menu.
- On the Home tab, under Image, click on Resize.
- Adjust the image size either by percentage or pixels as you see fit. Click on Maintain aspect ratio to keep the image size constant when adjusting by percentage.
- Click on OK when you’ve made your adjustments.