Slow progress bar in Windows Explorer folders (like downloads folder)
How to Fix Slow Loading Folders in Windows 7
To clarify, the load-delay can be seen in the directory box as a green progress bar that fills from left to right. Depending on how many files you have in a folder, this can take several minutes or even hours to load.
Locate the folder that is exhibiting the problem. The easiest way to do this is to be in a directory one level higher than the folder with the issue. Now Click the folder, ClickOrganize and Click Properties.
In the properties window, ClicktheCustomize tab. Under the “Optimize this folder for: drop-down menu,SelectGeneral Items.