For sake of testing... EDIT: I apologize in advance for a long post
For those too lazy to read a big long post, I got USB not detected in XP,
but after that I got it working! Read on for details.
I've got a WD Elements 500GB drive, formatted 100GB to WBFS, the rest to data, and it works.
I've got a Integral 2GB Flash Stick, in WBFS, which works with the only 2 games that I can fit on there.
I've tried a few GUIs, based off wbfs_win_delta, and they all work on my Vista 32bit laptop (haven't tried the other Vista laptop, not much point) and my Vista 64bit computer.
Now I try WBFSMAN (after installing the redist), and get the #9 error. Not much surprise there - everybody has been having it.
EDIT: I also tried various workarounds. Compatibility Mode (2000, XP, themes, no themes, etc) does nothing. Virtual Machines of XP didn't work. And using Vista Ultimate x64 computer didn't work either.
So I crack out my old Toshiba laptop (299MHz), running Windows XP SP2. USB not detected error. No surprise there either - others have reported it too.
Device Manager sees both partitions as normal, one it reads as RAW but has the correct sizes, and the other it sees as NTSC.
Other GUIs (stored on the Data partition for convenience on the other laptop) work perfectly (albeit based on wbfs_win_delta, so it may not be fair to compare).
I've restarted, no difference anywhere.
Next test I try; the 2GB stick. "USB Drive Not Detected! Plug In the Drive and Click Ok." Again, Device Manager shows it as normal - RAW format, auto-assigned drive letter D. Seems like there's no hope.
Being silly, I tried another test (which is more likely to cause problems than fix any) by having 2 WBFS formatted drives in at the same time. Now here's the surprising bit.
It worked. It couldn't detect the 2GB stick, but it fully detected and read the 100GB Partition. It even read all the renamed games (which makes up half of them) with the correct sizes and everything.
So this is where I stand.
It can work in XP, even if it tells you it can't detect the USB. I'll edit this post when I've tested out all of the functions (adding, removing, extracting, and making channels).
EDIT: The next batch of tests. Since having 2 WBFS drives in at once, it's worked, with or without. Taking out the 2GB stick still works. Putting back in my other exHDD (2x1TB in RAID, untested with Wii) still works (although it didn't when I first tried this setup). No matter where I try running WBFSMAN, it works (I haven't tried a directory with spaces though, or periods). For whatever reason, it works in XP SP2 (32bit) under any circumstance from the point when I put 2 WBFS drives in.
Adding, Extracting and Removing all work as normal. No bugs found, although it's very slow when it's only got USB1.1 (powered by mains) and 299MHz to work with.
Creating channels:
SSBB, selected it from the drive, browsed for the ISO in the same directory, worked. Output "USBP.wad". I'll test it in the Wii when I've got a few more.
Mario Galaxy, located in a different directory, still worked. Output "UMGP.wad".
Endless Oceans, located in a different drive (Extract from WBFS crashed because I knocked the laptop over whilst cooking - so I tried a faster testing method). Output "UFBP.wad". It seems like it's either random, or it goes through a list to keep them unique.
Mario Party 8, Extract from WBFS method. I find it strange that the status bar is located at the bottom, greyed out, where previously it showed disk space. I get the feeling that it's creating a large log file on the fly. Goes at 0.02% per second, and the ETA just keeps going up and up by 20 second intervals.
EDIT: Ultimately it failed. It seems that the log keeping updates on the status causes a memory leak, slowly running the CPU and RAM to 100%. If it didn't do this, it would've prolly worked just fine. On the other hand, I've tested the 3 channels I did create and they all worked perfectly (Wii v4.0E, preloader0.29, etc).
And so ends my battery of tests. I look forward to a Vista compatible release