Gf171122-c2r-flt.part03.rar -

You will need software like WinRAR or 7-Zip to extract the contents. Are you trying to:

Based on the filename , this appears to be a split archive file, specifically the third part of a set, typically used for distributing large files like software, games, or media. Format: RAR (a compressed archive format). GF171122-C2R-FLT.part03.rar

this file (and need help with the error "part 3 is missing" or similar)? Locate the other parts (1, 2, 4, etc.)? You will need software like WinRAR or 7-Zip