First you need to find out which version of windows you're running if its 32 or 64 then you can down either the 32 bit 2.4 (latest version) or 2.2e (older version) and if you have a 64 bit system you can download the 2.4 (latest version) or 2.2e (older version)
Fitcom - Technology and SEO with a side of awesomeInstalling and Configuring a WAMP Server in Windows 7 & 8