Why Microsoft Photo Editor Should Not Be Used
From Pvdwiki
The Issue
Most of the time, a digital photograph will need to be scaled down for use online or in e-mails. It may be tempting to use Microsoft Photo Editor since it is usually at hand.
DON'T!
Use Photoshop (or Photoshop Elements). The example below shows why.
Example
Here is a portion of an image that I had at hand that helps show a common issue that comes up using cheaper imaging software.
The original crop shown here was 1339x893 pixels. It was resised in Photoshop to 600x400 pixels.
Here is the same image resized in Microsoft Photo Editor to 600x400 pixels.
The Devil is in the Details
Here is the Photoshop image viewed at 400%.
And the Microsoft image viewed at 400%.
The difference should be quite obvious. Use Photoshop.