A lot of software is provided "free for personal use, licensed for commercial use".
For example, the FastStone Image Viewer is provided with these conditions:
FastStone Image Viewer ... provided as freeware for personal and educational use. In these cases, you are granted the right to use these programs free of charge. However, for commercial use, license is required.
Is it a commercial use when I install the software on my company computer and use it only to view my personal photos? (Of course supposed that the employer does not have a problem with using the company laptop for personal use, too.)