here is a handy tool call image resizer , this is a microsoft powertoy. it integeares with the os very well,
rightclick the image you want to resize , click "resize picture" , select any of the default size (or chose your custom size) , click ok , done
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, thats as simple as it can get
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. you can select to create a new file or change the oroginal .
Image Resizer
This PowerToy enables you to resize one or many image files with a right-click.
you can download it from this page link
direct file download link only 521kb.