OSDev.org

I don't know what goes on, every time I try to unpack the kernel sources in a FAT32/NTFS disk under Windows from the TAR-GZ file, there seems to be files with repeated names, for example (non-existing) ipc.c (with 350Kb) and then again the ipc.c (this time with 130Kb).

Maybe it's a bug in all of the available software under Windows to unpack the TAR-GZ files, or maybe the kernel sources have files in the same directory with names like IPC.C and ipc.c which could be differentiated under Linux but would be taken as the same file under Linux.

It looks like the only way to have a non-mutilated kernel is to unpack and work it under one of its distributions and of course a Linux-native filesystem partition.

have you checked
1) that you don't have a broken download?
2) that you use a decent archiver (i have bad experience with winzip/winrar) - Have you tried a windows build of tar/gzip?
3) that you are not unpacking to a filled directory?
4) that you are saving the archive to disk rather than loading it from the temp directory. (common cause of #1)

Sounds like the result of unpacking without directory names.

There are indeed several files with the same names, but they differ by directory, so you should respect the directory names in the archive to get it unpacked properly.