Windows 10: Restore Thumbnail Backup Photos to Original Size

I have found dozens of wanted thumbnail size photos (PNG files) on my old backup hard drive. The files have not yet been extracted. My question is how can I restore these thumbnail PNG files to original size?

Thank you

:)

 

When I open a photo, it opens only as a thumbnail and not full size. Is there any way to adjust this?

* Original Title: Windows Photo Viewer

When I open a photo, it opens only as a thumbnail and not full size. Is there any way to adjust this? Also I get many copies of certain photos, this happens randomly.

 

skydrive photo upload missing settings

Skydrive is made to backup originals of your photos so if you need a lower sized photo sent to skydrive you should reduce the size of the photo in the camera settings.

It would be ridiculous to backup anything but the original size as you are either going to view the photos on your PC in which case you want the original size for the photos, or you are planning on only viewing them on the camera and do not need large high
quality photos.

 

Not been extracted from what? You can resize them but they may well be very grainy depending on what size they were. Generally if it's a thumbnail enlarging it will make it unusable

 

Old backup files found on my old external hard drive.