Cannot format my USB Flash Drive after installing Vanilla Chrome OS

The disk most likely needs to be cleaned. Use the command line utility 'diskpart' to simply just wipe clean the entire device.

DISCLAIMER:

It is recommended that you use the Diskpart utility cautiously because Diskpart enables explicit control of partitions and volumes.

From Run: diskpart

1.list disk

Pay Attention Here What disk do you want to clean?

2.select disk # 

Replace # with the disk you're 100% sure you want to clean.

3.clean
4.create partition primary
5.select partition 1
6.active
7.format quick fs=fat32
8.assign
9.exit

See MS article here for more info: http://support.microsoft.com/kb/300415?wa=wsignin1.0

I ususally solve those strange situations with usb dongles with the

HP USB Disk Storage Format Tool

you can find it on Google