regeneration time help

#1
i am using intellicad ver 6 with P4/2mb ram with latest configuretion when we open drwing. of file size more then 3-4 mb it takes around 300-400 second but same with acad 2002/2000 version time taken about 10-15 sec. same problem occure while operating cammands
pl help us to sort out the problem
regards
pankaj