ankur rathi wrote:Can't do that due to some reason.
This is starting to sound like an overly constrained problem.
You could use something like Laplink, which can use USB or serial cables, and if you buy the right version, the cables are included in the box. But from a practical view, its all the same whether you use Ethernet cable, WiFi, or special LapLink cables. Its a network connection, and then you can use either general software such as rsync or "scp" or the LapLink software.
From a practical view, its all the same.
You could use "sneakernet" or even "floppynet" which just means plugging in a USB dongle or floppy, copy the files, remove it, plug into second computer and copy again. But its really isomorphic.
With any connection, you want to use checksums rather than file system dates, and you need to detect and handle when some files are changed on each system. tools like CVS, SVN and GIT do this, but they assume a network.