CPUID and the Web

I'm trying to have a website uniquely identify a user's computer when they come to the page for certain security and stat features. I decided not to go a MAC/IP address route for a few reasons and decided to try getting the cpu serial number instead. This has presented a problem to me however. I have found out that you must use assembly code (function "cpuid") to get the information, and hence an inline assembler. My pages are constrained to using something the fits into ASP/VBscript/Javascript or ActiveX. I do not know a way that I can get assembly code to run with these. I found C++, VB, Perl, etc versions of code to get the information I want, but does anyone know how I can get it on my webpage using the above technologies/langauges? Links, examples, overall advice? Or does anyone have another suggestion on how I can uniquely identify a user when they come to the page (without a login/password entrance)? Thanks