Windows 7 - Problem with windows photo viewer

I am guessing at this but several things come to mind.
1. Panda AV? Is it a suite AV
2. Add on's at startup
3. Is the laptop and desktop networked together? Sharing
Just trying to help as these would be things I would look at to get Win 7 working.

It's Panda av pro 2010. It has anti-mallware/spyware protection.
Don't know about any unusual add on's on startup.
The laptop and desktop are on the same network but laptop is wireless, desktop with a cable. Didn't share filess. I don't think Windows 7's behaviour is caused by networkproblems. I really don't know what causes this OS to do it's job so poorly on 2 totally different computers.

Do you have your files set to open in the same window or a new one? Look in the Folder Options located in the control panel.

Same one. Problem solved btw. I didn't do anything. Suddenly it worked as it should after 3 weeks of frustration.. No idea what caused this problem. Didn't uninstall or changed anything meanwhile. Thanks for the reply's guys!