This is probably the simplest method for creating an image with rounded corners. It can be done using the free image editor Paint.NET. There is also a step-by-step article here if you prefer not to watch the video.

THUMBS.DB is a file used by versions of Microsoft Windows that stores a cache for Windows Explorer’s thumbnail view. These files end up everywhere on your hard drive where you are working with images. They are annoying. I like to prevent these things from being created. Here’s how:

1. Hold down the Windows Key and press R, type regedit and click OK

2. Click the plus sign next to HKEY_CURRENT_USER
then Software
then Microsoft
then Windows NT
then CurrentVersion
then Program Manager
then click on Restrictions

Create or edit the DWORD value NoSaveSettings. Give it a value of 0.

After you restart your computer, Windows will stop creating Thumbs.db files.