The only way is using a Parasolid format, STEP or IGES.
The other way is to install a copy of newer version along the 2010, then, open the 2011/2012 version and save as parasolid and open in 2010, but I advise strongly against doing so. To make it work, you'd need a separate partition with a separate OS with a proper standalone SW installation. That means dual boot.
Really strange, never heard of that one before. To be honest, I think the 'no backward compatibility' is just a game to force an upgrade, really hate that. But off the topic again.
Hello Robert, I've had 2010 and 2011 installed at the same time on the same OS and partition, they worked perfectly, actually they crashed a lot but that's not because of one effecting the other. I guess you just need to be careful with installation locations.
No separate partition is required. You can install as many versions of SolidWorks as you like on a single OS installation.
the problem is that i dont have sw2011.....
and i cant download it bcoz of low speed of net :P :(
any other way to converting it into parasolid format ... ??
Well, I tried once with my current 2010 and a borrow copy of SW2012. Followed all the steps, went smoothly, opened both, appeared to be fine at first, however, within the next few days my 2010 version started to go crazy. The first glitch appeared to be the lack of capability to add a dimension to the sketch on a new part. Then it went from bad to worse. Anyway, I made a system restore and my copy of 2010 went back to normal. I'm waiting for the company that fabricates laser cut and sheet metal parts for us to upgrade, and then I will upgrade as well. To be honest, none of the new features in SW2011/12 give me any special benefits for the work I do.
Anyway, this is way off from the question asked.
as Rohit and Wolf said above, you don't need separate partition. I once had three editions installed.
Yes, if the model is here on GrabCAD ask on its page for a Parasolid, and if not, upload the model here and someone will convert it for you.