After searching around on the net trying to find an easy way to create and apply patch files, I came up with the following free solution that creates linux compliant patches.
1. Download and install patch and diff from the GNUWin32 Project http://gnuwin32.sourceforge.net/packages/patch.htm and http://gnuwin32.sourceforge.net/packages/diffutils.htm

2. Navigate to the place that the exe's were installed (eg. C:\Program Files\GnuWin32\bin)
3. Create a new file called patch.bat and put the following code in the file:

@echo off
"C:\Program Files\GnuWin32\bin\patch.exe" < %1
pause


4. Create a new file called diff.bat and put the following code in the file:

@echo off
"C:\Program Files\GnuWin32\bin\diff.exe" -u %1 %2 > %1.patch
pause


5. Find a .patch file (or create a new text document and change its extension to .patch). Right click this file and choose Open with...->Choose Program. Browse to the patch.bat file.
You should now be able to double click a .patch file to apply it (NB the patch file should have the same name as the file to be patched, with .patch appended to it)

6. Go to the Start menu->Run and type "sendto"
7. Create a shortcut of diff.bat in this folder
8. You can now create a diff file by selecting both the original and modified file with your mouse, right click ON THE ORIGINAL file and choose diff.bat. A new .patch file will be created.