I am looking for a Windows software that can simulate handwriting, so I write on my keyboard and get handwriting word as a result
Here's a Lifehacker 'how to' on the use of website that converts your own handwriting to a font: http://lifehacker.com/206685/geek-to-live--make-your-own-font
If you do go down the fonts route you could use this site:
Link: http://www.identifont.com/
to help you to choose the font that suits your requirements most closely.
Best solution by far is "My Font Tool for Tablet PC" PowerToy from Microsoft (see http://www.microsoft.com/windowsxp/downloads/powertoys/tabletpc.mspx ) In the extremely likely event that you don't have a TabletPC available, find a Wacom style tablet and plug it in to a PC running Vista ( other than "Home Edition") to generate the fonts.
You just need the proper font. If none of the fonts bundled with Word suit your needs, you can find more on the internet, e.g. free handwriting fonts (found through google, no own experience).