no
There is no demo on the PC
No.
Yes, it's in the 'Sonic Mega Collection Plus', it's a bit old now so you might have to hope you can get it second hand from somewhere.
you can't get the pc version and use mods there
It was originally to be released for PC, but was cancelled. In addition, the Wii port was cancelled in favor of Sonic and the Secret Rings.
There is no demo.
For Lego Harry Potter, there is no PC demo.
i don't believe that there is a demo in PC only in xbox 360
no there is not for PC but there is for ps3 and xbox360
The PC Demo lasts 5 in-game days (1 hour 20 mins) and the PC full version lasts forever
You can't yet. The demo is available on PSN and Xbox Live, but not yet on PC. Search the internet for exact date of realse of the demo.
Not at the moment, there will be a demo on the PC, possibly not the 360