The Nexus Client is compatible with FOMM. To install NMM:
- Install NMM.
- Uninstall FOMM.
- Start NMM, making sure to use same Mods and Install Info paths as in FOMM.
The order of steps 1 and 2 don't actually matter.
If you already have NMM installed, just install the latest version over top; there is no need to uninstall the old version.
NMM is not compatible with OBMM. If you would like to use NMM to manage your Oblivion mods please:
- Uninstall all Oblivion mods.
- Uninstall OBMM.
- Start NMM for Oblivion.
- Add and reactivate all mods.
Kaburke can explain this issue much better than I can, but in a nutshell, if you install NMM over the top of your current OBMM then you won't be able to uninstall any previously installed mods. Even if you activate and deactivate them. This is obviously an issue and ideally we don't want to be handling support for this.
Your other option is to continue using OBMM for Oblivion but use NMM for the other Nexus games. You can do this no problem (so use OBMM for Oblivion, and NMM for Skyrim, for example). Ideally we'd love you to be beta testing NMM and just NMM, but we understand some of you don't want to uninstall and reinstall hundreds of mods. So it's your choice.