Core i3 Questions

if you want to use cpu's integrated gpu, you will have to connect the display to your motherboard's one of the display output(s) provided that your moptherboard supports integrated gpu usage. if your motherboard is a z-series chipset, you can use lucidlogix's virtu software to use both igpu and discreet gpu. refer to lucidlogix site for more info.
gt430 is better than core i3's hd2000 igpu. you should connect your display to the display device of your preference (hd2000 or gt430).

if you want to use hd2000, then you will have to instll the hd graphics drivers after you install windows.

Did it work on Core i3?They say "Virtu has been designed for Sandy Bridge platform H Series (H61/H67 and Z68 platforms) with 2nd Generation Core i5 or Core i7 CPUs."Is it true?I've H61 Board.Thanks.

ah. you're right.
http://www.lucidlogix.com/product-virtu-gpu.html
i wasn't sure about your motherboard model.
i've always thought virtu was about the igpu and not dependent on cpu. however, i don't see mention of core i3.
as for your first query, if you want to use hd2k igpu (without virtu and not use gt430), you will have to connect your display to the h61 motherboard's appropriate display outputs. then you will have to install intel hd gfx driver after you install windows 7.
i mentioned virtu in case you wanted to use both igpu and the gt430. you could test it out yourself if you want.. to see if it works with core i3.

Thanks a lot.