There is possibly nothing more annoying than having your power supply weigh more than your computer. This isn't EXACTLY the case with the MSI Wind U90 but it very nearly is. As such, it was ridiculous to carry around the power supply it came with, since the power supply took up more room in my bag than the computer did.
We found a 24V AC Adapter, which although the MSI suggests 20V it runs fine on 24V. (These are readily available at any electronics store). Then the connector was changed to one that would fit the MSI, a standard DC connector. An easy do-it-yourself project, we hope we can pass on the knowledge to other MSI owners.
While we were at it, we thought making the MSI available for long car trips would be great. We made a boost converter, boosting from 12V in the car to the 20V needed for the MSI. Rather than using a standard power supply integrated circuit (chip) we decided to use a microcontroller so that we can add intelligent battery protection. The microcontroller generates the pwm signals for the boost converter and measures input and output voltages. It checks the input signal and only turns on the output only if the car battery is over 13V - meaning either the engine is running or you have a really good battery. If the car battery goes below 11V (a problem in our slightly used car) it will shut off the power supply to the laptop.
Schematic and do-it-yourself instructions coming soon.