File access denied error

I am running webcamXP free with 2 USB cameras. It used to work fine but now I get file access denied errors. They first occur on start up but I can avoid those by running as administrator. However I still get them when I try to connect a camera. I have uninstalled the program and reinstalled the current version and also restarted the PC. The cameras are working fine when using the Logitech software. Any suggestions? (I am running Win7 home premium.)

If it has been ran as administrator once or from other user account. maybe some files have now limited access.

try to change the rights on the folder:
C:\ProgramData\webcamXP 5

or try to rename the folder temporarly and see if then the problem is solved (despite settings will be lost after doing so).