He remembers everyone, its just that the dark side clouded his mind.
Darth Vader remembers that Anakin Skywalker once thinkered with and repaired a protocol droid he offered his mother as a young boy. (as is seen in the Star Wars comics). However, if your question actually is "does he recognize C-3PO?" then the answer is "No". The sight of the broken droid triggers the old memory in Darth Vader, but his casual inspection does not identify the droid as the one he repaired so long ago.