Have noticed when running windows disk cleanup that the thumbnail cache size (which I leave unticked) seemed to be getting rather large at at nearly 200mb. I wonder if thumbnails are stored everytime I pop an SD card from the camera in use explorer to view them and dozens of photo thumbnails appear... is it clocking those up perhaps.
The "Explorer" folder these are in is viewable with the following file path, C:\Users\ username>\AppData\Local\Microsoft\Windows\Explorer
I also have a collection of small .jpgs that I use for customising many folders and subfolders stored in "pictures" and I use the customise option to pick a piccy for each folder.
Anyway, decided to delete the cache using disk cleanup and rebuild the custom folder pictures. Result, the size of the cache is now 30mb, down from 200mb. Also, and I can't see the connection, but I feel boot times are quicker from doing this... will keep a check on that... certainly seems so at the moment.