You can't find a specific file which had been deleted from the Recycle Bin:
If you placed the file in the Recycle Bin before deleting it, it may have been renamed by Windows (a standard feature). In this case, the best way to find your file, is to list all files in the Recycle Bin and then sort by the last modified date or by the file size.
For more information on the Recycle Bin and how files in it are named, see this topic.
Recuva cannot determine the file system type for the drive your file is located on:
You still can't find a specific file or files:
In this case, we would recommend using the Options > Actions tab to enable all of the Scanning options except Deep Scan, then run your scan again, to ensure that Recuva does not mistakenly filter out your file(s). However, if even that does not you to locate the data, and the file(s) are in a supported format, please try running a Deep Scan. Keep in mind that this may take several hours, however.
You used Recuva to securely delete a file, but you can still see the file name in Windows Explorer (or other Windows programs):
This is expected behavior. Recuva does not overwrite file names for securely deleted files - only their contents. If you try to open the file in its associated program, you will typically find it's impossible.