Hi guys 'n gals,
This lack of thumbnails for JPEGs was driving me bananas

, and I tried absolutely everything suggested here and elsewhere, including resetting the BagMRU and Bag values in the registry (see the link below ..... be sure always to set up a restore point before fiddling with the registry!), but not as far as the total back up and reload (I've only just gone through the usual 48 hrs of hell with the update clean install!!), however, to no avail, and in my line of business, I have to see an array of many JPEG thumbnails to select the one or ones I need to work with.
However, I had a wee thought ( a rare event): I had previously selected my favourite bitmap editor, Corel PhotoPaint 4X, as the default JPEG editor to use when opening files from a list by left-clicking on them. I went back in to change that [right-click on any JPEG file, choose 'Open With' from the drop down menu, then from the subsequent drop down, select 'Choose Default Program' (at the bottom of the menu].
All of the programs capable of opening the JPEG image will appear.
I selected 'Widows Photo Gallery' from good old Microsoft, closed the resulting image once it appeared, and, voilá, all of my JPEG icons changed back to thumbnails, providing I selected anywhere from medium to extra-large in the 'Views' drop down. Now when I look at the contents of a graphic folder in and of the Corel programs, all the JPEGs appear again as bitmaps, and of course will open in Corel Photo Paint.
If one were to left-click on a JPEG file out of the Corel environment, it will of course open in Windows Photo Gallery, a small price to pay for being able to see thumbnails again. However, right-clicking on the file even when not in the Corel environment will also allow me to open it in Corel using the 'Open With' command in the drop down menu and choosing 'Corel PhotoPaint' from the displayed options.
I believe this is a quick and easy fix for all of us who really need to see our JPEG files as thumbnails, especially when we are working with many, many files. I did go through the registry fix dexcribed elsewhere, namely:
'Delete and Reset Windows Vista Folder Views or Folder Types Settings
to Default Clean State » My Digital Life'
(
http://www.mydigitallife.info/2007/1...t-clean-state/)
(and everything else anyone suggested in the other Vista-related foums) till I was blue in the face

and I had thoughts of my current computer becoming an expensive anchor for a small boat ...... the dreaded word 'MAC' even drifted in ... anyone reading this from Vista, take heed!! I therefore have no way of knowing if that registry re-set was actually required in addiiton to my approach, or if simply resetting the default viewing program to one with the blessings of Microsoft would do the trick.
Hope it works for anywone else in the same pickle. I have just wasted the best part of a day getting this small but niggling problem right, but it's worth it. Happy thumbnailing!