connect macbook air to pc via ethernet adapter
trying to move files from pc to macair via ethernet adapter without success
Are you trying to direct connect the 2 machines or are you using a network router?
If you are trying to direct connect you need a special ethernet cat cable called a crossover cable.
http://support.apple.com/kb/HT1408
You can always use sneakernet and use a USB flash disk formatted FAT32 to copy the files on your PC and then copy them on your Mac.
You can use a free dropbox or box.net account to transfer the files over the cloud.