I use WAMP as my server of choice but a few months ago I installed a new version. After installing this some of my sites stopped working, I tried to change from PHP 5.3 to PHP 5.2 and PHP wouldn't work. At this point I put my old version back on and didn't think about it.
Last weekend I reformatted my computer and I put the new version of WAMP on. Same problem.
After checking the logs I noticed Curl wasn't working. I tried different versions of PHP and MySQL and none of these worked.
Then I started checking the forums for the problem, I checked all over the place but to no avail. I stumbled on a few places telling me 32bit runs fine on a 64bit computer (I have a 64bit computer) then I read none of the modules work on the 64bit version of WAMP (even the 64bit compiled version).
Basically, 64Bit version of WAMP is broken, do not use it.