PingEnhancer does mainly the same thing like Leatrix Latency Fix, but it has an ease of use windows UI, and contains an additional tweak for Windows Vista/7.
PingEnhancer supports following operating systems:
Windows XP (SP2 or higher)
Windows Vista (SP1 or higher) 32/64-bit
Windows 7 32/64-bit
PingEnhancer will modify following keys in the registy (you need administrator rights):
NetworkThrottlingIndex (only Windows Vista/7)
I recommend to use the "Optimize" button, it will use the best settings.
PingEnhancer is free of viruses, trojans, spyware, malware, and worms.
It does not establish any connection to the internet.
It also conforms to Blizzard's EULA, ToU and UI Add-On Development Policy.