Dear all,
I have tried now several searches in this and other forums, and have tried several suggested solutions and nothing worked. Therefore I have decided to start a new topic.

I have played a lot with my N900. I have installed Power Kernel Nitroid and Meego/Nemo images on and off and I have reflashed the device also several times. I didn't experience any big problems so far.
Now I tried to reinstall the power kernel and multiboot, because I wanted to compare battery performance again.

After I have restarted the Multiboot selection appeared, but with my old settings. there were only listed the original kernel and Nitdroid. when I select the original kernel I get a Guru meditaion (unable to load kernel), when I select Nitdroid of course it doesn't start as Nitdroid was deleted some time ago.

Therefore I said: ****!

And then: I should try to reflash the kernel using the Wiki on this page.

But: The N900 isn't recognized correctly by windows any more. When I connect (after starting the flasher) it is only recognized as "unknown USB device". The flasher claims of course nothing suitable found.
I have now tried several things so far:
1. reiinstall flasher
2. Install Nokia Suite
3. Use Unbuntu live CD with linux flasher
4. Use a different PC (all of them with Windows 7)

Anybody any idea? The battery is charged. I am using the original cable and also a USB port that had already worked for the flash.

I am more or less helpless...

Thx.

The correct answer is to install flasher-3.5 for Windows and use the latest libusb (grab it from Sourceforge) -- it doesn't need Windows' test mode driver signing any more.

Yep. Tried that, too. (Forgot to put in the list)

When I execute the .inf-wizard. The N900 is listed, but with only 0x0000 for vendor and product ID.
If I try to manually change that, there is an error message, that the entry already exists.
It seems that the N900 doesn't give its correft ID anymore for some reason.

Thank you for the help sof far