We are using Autocad Architecture 2008 in Windows XP professional edition.  Our PC specs is ACER VEriton M661-675P (vPro Technology), Intel Core duo E6750 (2.66GHz/4mb Cache), Intel Q35 chipset + ICH9do, 2g-4g DDR2 mem, 160-320 HD, ATI Radeon HD2400PRO 256MB.
 
We are experiencing a very slow start-up of CAD application (you may want to sleep before autocad opens).  During drafting, some commands, like layer and plot, take ages to activate.
 
Please assist us.  We are dying!!!

This may be caused by an antivirus program, by a communication problem (e.g. the InfoCenter tries to connect to the Internet) or by certificate communication - in Internet Explorer go to Tools > Options > Advanced > Settings > Security, and clear the "Publisher's Certificate Revocation" checkbox.