Install BF from disc
Reboot
Install FS
Reboot
Install BF 1.25
Reboot
Install FS1.25 hotfix
Reboot
Install BF 1.4
Reboot
Install BF 1.5
Reboot
Install PB
Install EA download manager
Reboot

Hurrah success, have tried most maps by creating server and trying on my own.
Fantastic mod, thanks.

Just got to figure out why I cant see any servers...

I found the regedits for a manual uninstall somewhere on web, wish I could credit the author but its lost now. Here is the edit anyway.

The BF series of games stores its install information in the registry, you need to manually delete the registry information before the computer will re-install the game. Use the following method recommended by EA tech support to manually uninstall;

Quote:
To delete the configuration files and local copy of your account:

1. Double click on My Documents.
2. Right-click on the Battlefield 2142 folder and choose Delete.

To delete the game files (in the default location):

1. Open My Computer.
2. Open the Cdrive.
3. Open the Program Files folder.
4. Open the EA GAMES folder.
5. Right-click on the Battlefield 2142 folder and choose Delete.
6. Go to the following folder: C:\Program Files\InstallShield Installation Information (If you cannot find this folder you may have to go to Tools > Folder Settings and click the setting to SHOW hidden folders.)
7. Right-click on the folder named {ED50ECE9-EC54-4C05-B5ED-EE4741A9F2EC} and choose Delete.
8. Close all open windows.
9. Right-click on the Recycle Bin and choose Empty Recycle Bin.

To edit the registry and remove Battlefield 2142:

1. Click on the Start button.
2. Click on Run.
3. Type regedit in the text field.
4. Click File and then choose Export.
5. Name the file Backup and make sure the Export Range is set to All.
6. Click Save; you will now be returned to the Registry Editor window.
7. Click the plus sign next to HKEY_LOCAL_MACHINE.
8. Click the plus sign next to Software.
9. Click the plus sign next to EA GAMES.
10. Right-click on the Battlefield 2142 folder and choose Delete.
11. Back under Software, click the plus sign next to Electronic Arts.
12. Click the plus sign next to EA GAMES.
13. Right-click on the Battlefield 2142 folder and choose Delete.
14. Just above EA GAMES you will see a folder named EA CORE, click the plus sign next to EA CORE.
15. Click the plus sign next to INSTALLED GAMES.
16. Click the plus sign next to EA GAMES.
17. Right-click and choose Delete on any Battlefield 2142 folders.
18. Click the plus sign next to Microsoft.
19. Click the plus sign next to Windows.
20. Click the plus sign next to CurrentVersion.
21. Click the plus sign next to Uninstall.
22. Right-click on the key named {ED50ECE9-EC54-4C05-B5ED-EE4741A9F2EC} and choose Delete.
23. A Confirm Key Delete window will appear, choose Yes.
24. Close the WindowsRegistry Editor.

Battlefield 2142 is now completely removed from your system.

Worked for me.

Complete noob question, fs2.0? fs2.25? thought the latest versions of fs were 1.2 and 1.25 hotfix?!

After 3 more tries downloading fs from different sites I found one without a corrupt common_client file.

FS 1.25 hotfix now installs. Applied 1.5 BF patch. Now neither BF or FS will run, ie no further than the small splash image of the walker before the screen goes black.

This sounds like a BF problem and not a FS problem, unless someone knows otherwise.

edit: after much searching it seems there is sooo much more to do when uninstalling than I did. Installing 1.4 is necessary as stated. Seems you need to start messing with the registry to really uninstall everything. And get rid of EA download...

Also, I installed to external drive, durr, so will have to reinstall anyhowz.

Ok so I think I have done my research and have tried to install this mod correctly. To summise:
Uninstalled BF2142 1.5 including punkbuster,
installed BF from disc,
installed FS,
installed BF1.25,
tried to intall FS1.25 hotfix and got the following err message:
drive letter\sub-dirs\mods\FS\common_client.zip: unknown version

If this worked I would then:
install BF 1.5
install Punkbuster

Any ideas?

Thanks