When you say HTTP, what browser are you using or is this just a general thing?
You say "even when using a localhost server", just to rule it out, I wrote a blog post about (very) slow load times in firefox. If using Firefox, type
about:config in the address bar and look for
network.dns.disableIPv6 - set this to true and it should speed up.
If however you are saying it is slow no matter what program you use, the best advise I can give is to simply try updating your network card driver - Windows 7 (as good as it is) comes with a few bad default drivers (especially, but not solely for Realtek network cards).