I got a strange bug the other day, where my Windows 7 icons would disappear, simply reverting to blank icons, even tho right clicking on the icon > properties, resulted in an image of the programs icon. So I did a quick search and found a valid solution… to delete your icon cache.  I was a little hesitant to just delete something, so did a little research and found that this was harmless.

Here are the steps to get your icons fixed:

1. Press Ctrl-Shift-Escape to get the task manager.
2. In the Processes tab, click on explorer.exe and click End Process. You’ll get a confirmation dialog. Click “End Process” to confirm.
3. From the File menu (still in the task manager), choose New Task (Run…).
4. Copy/paste/enter the following command in the run box:

   cmd /c del %userprofile%\AppData\Local\IconCache.db /a

5. Open the Run box again with File –> New Task (Run…). This time, enter this command:

   explorer.exe

6. All should be okay now. Open the Start Menu and confirm that your icons are fixed now.

That should get you back into working condition (worked perfectly for me, or I wouldn’t post it).  All icons show up now.

Reference:
http://www.sevenforums.com/general-discussion/9973-icons-not-showing-up.html#post356016