Chris Double has released a new version of the Nintendo DS emulator for Windows called DSemu, heres whats new:

DSEmu 0.4.6 is out with bug fixes, a new logging window, an implementation of SRAM, and a more correct implementation of vram mapping. Some of the more recent demo's are emulated close to 100%. These include Teenage Queen, and WinDS. This release also incorporates a number of fixes and improvements from contributers other than myself. A big thank you to all those who contributed.

* VRAM mapping is more correctly emulated. Demo's that didn't correctly show both screens should start working now. Most notably this allowed WinDS and Teenage Queen to work.
* Various bug fixes to solve crashing problems.
* Fixes to enable console text to display with DevkitPro r15 compiled applications. Unforunately this fix breaks console text displayed by applications compiled with earlier versions of DevkitPro. If you wish to run these applications in the meantime I suggest using DSEmu 0.4.5. I hope to have this resolved in the next release.
* SRAM support contributed by Ryo Sazaki. This adds a new file menu allowing saving the contents of SRAM and loading data into SRAM. As an example, the SRAM tutorial now works.
* A log window has been contributed by Troy Davis. Using 'View/Log' in the menu will display it. When using the debug SWI 0xFF the message will be displayed in the log window.
* Some of the code was cleaned up by Julien Hamaide so the number of compiler warnings is reduced. Julien also fixed a problem with the square root SWI.
* Unfortunately a problem has surfaced with a few demos crashing that did not crash in previous releases. Strangly these happen only in the release version of DSEmu 0.4.6. If you build a debug version from source they run fine. I hope to have this fixed in the next release.

Download DSemu Here --> http://nintendo-ds.dcemu.co.uk/dsemu.shtml