Open the WINDOWS\MSAPPS\PROOF folder
Do the following while in 'Windows Explorer':
1) Select (double-click on) the WINDOWS folder in the 'All Folders' list box. (All subfolders within the WINDOWS folder appear under it.)
2) Select (double-click on) the MSAPPS folder in the 'All Folders' list box. (All subfolders within the MSAPPS folder appear under it.)
3) Select (single-click on) the PROOF folder in the 'All Folders' list box. (All files within the folder appear in the Contents of Proof list box on the right-hand side of the Exploring window.)