I have a cd of "need for speed 2 special edition" cd.I copied the entire Game to HDD and then converted it to ISO File and tried to run it form virtual cd rom,but it can not run.it run from cd rom directly.

That'll be the copy protection then ;)

You need to find a No-CD patch, sometimes game developers release them (in the cases of starforce, which is regarded to be troublesome, so developers generally just put it on for initial release, then provide a patch to remove it some months after release), but mostly they are illegal and you will be getting no help here.