I encounter recurrent problems with the geoalgorithms that perform interpolations.
No matter what technique I use I end with the following errors. As stated in the OGR tab QGIS 2.0 is unable to open a file in C drive.
I have very little IT background so the message error is meaningless. 

Is there anybody able to decrypt the message and solve the problem?

![enter image description here][1]

![enter image description here][2]


here this is the algorithm i used

![enter image description here][3]


  [1]: https://i.sstatic.net/BlLnX.jpg
  [2]: https://i.sstatic.net/gjkqe.jpg
  [3]: https://i.sstatic.net/kfYAk.jpg