I have an external sound card is roland 2 duo

Yes, you can record with any version of sonar with your PC. Just like every other PC, the more you have in a project, the more your PC will work. The more your PC works, the higher the CPU will go. To lower your CPU, just adjust your ASIO buffers or WDM slider to relieve the stress. 
 
CJ

I see you have a roland soundcard....I think you need to run WDKMS audio driver...with proper driver from roland...
 

CJaysMusic any lower and om getting a sound delay

Hi shawn i used the cd that came with the product ..can you please explain?...im little lost

You'll find the latest drivers for you interface here:
 
http://www.cakewalk.com/download/hwdrivers.aspx?Prod=UM-2G
 

"Hello friends ,i was thinking to replace my hs7 with x1 or 2..."
 
I did not see any comments like "X1/2 is not available anymore...", but I assume the practice is as always: The older versions disappear from the shelves very quickly after a new one is published.
It might be X2 is still available somewhere (as it's still the latest demo there is), but it might be harder with X1.

Unfortunately your computer does not have a sufficiently large penis to use for music production. Many people think that a low end off-the-shelf computer with an average sized penis is capable of making music, but clearly this is not the case. A quick survey of electronic music forums will give you some idea of the immense member your computer should be sporting in order to enter the world of audio editing, let alone sound synthesis. Opinion varies about whether a large hairy ball sack is necessary for basic music production (most agree that a well stocked scrotum is a must for large track counts), but a large penis is definitely a must.