File Sharing Mac OS X 10.4 to Windows 7

The troubles with getting a Windows box to see a Mac usually falls in the area of which workgroup the Mac is in and the user account. This Apple technote describes the process that would be used.

Apple TechNote

If you are planning on connecting to the mac consistently then follow the link above. If you don't want to deal with that and simply want to transfer files now and again then go down the SCP route. Enable SSH access on your mac for your user account. Then from your PC you can SSH/SCP/etc... to the Mac with something like PuTTY.

Windows Vista and 7 only support NTLMv2 auth. You will have to dumb down Windows security policy to accept NTLM and Lan Manager authentication. Open secpol.msc and choose Local Policies>Security Options. Double click Network Security>LAN Manager Authentication level. Change from NTLMv2 to NTLM and LAN Manager - Use NTLMv2 if negotiated. Then in Network Security>Minimum session security for NTLM SSP Based Clients uncheck require 128 bit. Hope this helps. Also make sure the Mac and PC are set to the same workgroup.

Complete instructions about how to share files between Mac OS X and Windows 7, can be found in these tutorials:
How to Share Mac OS X Folders with Windows 7
Access Windows 7 Shared Folders from Mac OS X

how about using Dropbox or Googledrive ? that will be easy to handel

You can also hook up a Cat 5 cable to the PC and Mac and establish a sort of "private network" to where you can transfer files via (I think) adp.

You can also connect via smb to the Windows server, provided you're sharing a drive.