I know this sounds like an idiotic question but I have never had this problem before and I can't figure it out. I can't open Wrye Bash at all. I double click the launcher and nothing happens. I just upgraded to 290 so I assume it's something wrong with that. Anyone have any ideas?

It seems to be a problem with 290. I had to ask the other day too. If you go into the MOPY directory there's a file called pidfile.tmp which you should delete. It should be deleted automatically when you exit the game, but as I understand it version 290 doesn't do this. so it needs to be done manually. This issue is fixed in the yet to be released update I read in the thread.

Correction: It is created by Wrye Bash v290 as a lock file while Wrye Bash is running. It should be deleted by Wrye Bash when Wrye Bash closes. Some users seem to be experiencing this file being left behind after Wrye Bash closes, and causes Wrye Bash not to open at the next run. (Hmm, one thing I dont do is launch Oblivion from Wrye bash - Dont know if thats related, but I wonder if people firing up the game directly from Wrye bash could make this file get left behind)

If Wrye bash is not running, and you find the pidfile.tmp in Mopy\, delete it. If you are un-lucky enough for this situation to re-occur then unfortunately at the moment you need to live with it until the next release of Wrye Bash (it has already been fixed for that release)

It happened once for me, but since the first deletion of that file has not happened since, I am happy with v290, but you could revert to version 287 (288 and 289 are buggy) if not happy Your choice, If I had the problem personally even though its a pain I would still use v290 and just ensure the file was deleted before running Wrye bash.

That's the problem I have too. I don't have the pidfile.temp either. Right when I get finished installing it and try to open it, it doesn't do anything.

I had the same problem, and I tired to create the http://wryebash.netai.net/#IfBashWontStart, but instead it started Wrye Bash, so I think this should work for you as well:

? Open a command shell (Start: Programs: Accessories: Command Prompt).

? chdir to the Mopy directory. "chdir" means "change directory". E.g.: chdir C:\Program Files\Bethesda Softworks\Oblivion\Mopy

? Type: c:\python25\python.exe bash.py -d

? If you have a different version/location of python, adapt the first argument accordingly. (I had python 26, so I used pyhton26 in the command here instead of python25)

You can actually just double-click on the Bash.py file in the Oblivion\Mopy folder and it will run for you. You probably don't need to do it from the cmd prompt.
It is preferable to use the Wrye Bash Launcher.pyw if you can though. It handles some things that Bash.py doesn't.

Another alternative is to replace Wrye Bash Launcher.py in v290 with the file from a previous version.