Hi,
I am a little confused about your state. Just as your mention, how can you use Windows Photo Viewer to place .jpeg pictures in word documents, except that, where
do you import the bad image then it looks fine. In addition that, we also want to know whether you changed the device such as monitor or printer. Could you please describe the issue more detailed?
However, just as we known, the picture is consisted of a number of pixel. Each pixel has different color level so that we can see a complete picture. Have you
ever tried open others of which picture extension name called PNG or GIF? I infer the reasons for the issue is color profile corrupt or color settings.
Firstly, you can try to open Control Panel, then type Color Management in search box and click it. Check the box Use my setting for this device > Add
> ChooseSRGB IEC61966-2.1 and set it as default. Then click Advanced tab, and make sure that check System Default in all the column if you havent changed any device.
If the steps above doesnt work, you can right click desktop > Personalize > Change Display Settings > Advanced Settings > Color Management,
then choose your device in the drop-down list.
Also, if the issue occurred suddenly, you can try to perform System Restore to make the PC back to the point which use normally.
http://windows.microsoft.com/en-us/windows-8/restore-refresh-reset-pc
Wish you will troubleshoot the issue smoothly.
Best Regards
Simon