Solution:
NOTE: You should create a backup of the registry before continuing.
1. Go to Start>Run and type in regedit and click OK.
2. Navigate to:
HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\WINDOWS\CurrentVersion
3. Highlight the CurrentVersion node on the left side, but do not expand it (ie. do not click the + sign next to it)
4. On the right side, there should be a ProgramFilesDir variable.
5. Double click it, or Right Click>Modify.
6. The 'Value Data' box should have your Program Files directory. (default: C:\Program Files) Make sure you copy it down somewhere, and then change the value to a folder on a partition which has enough free space to patch BF2.
7. Close regedit, and then run the v1.12 patch.
8. Once the patching process is completed, follow steps 1-5 again, except this time change the 'Value Data' back to what it was originally. (NOTE: If you do not do this step, your system may become unstable.)
certes en anglais mais comprehensible !!!!