Files will not open

Someone please help me. I seem to have difficulty opening files on certain programs I have. I keep receiving these error on certain programs:

1.) Error Cannot open file:/C:/example.xxx
2.) The file format of C:\xxx\xxx.xxx cannot be read by program. Please ensure that the affected drive is not full or write protected.

I don't know if these files are damaged or not. If anyone can help I would deeply appreciate it.