i don't use scrapebox, but it can be useful for torrenting as well as portalweb said
however Windows doesn't limit these connections from and above Vista SP1, so it's only useful for Windows operation system which is older than Vista SP1
i tried a similar method on Win XP Pro SP3 to increase these half-open outbound TCP connections limit with a .bat patch file from the utorrent forum, because whenever i started seeding 7-8 torrents, utorrent made my internet connection disconnected, so the patch made a backup from the original tcpip.sys & did its work well
it's another question that utorrent 2.2 has some serious fuckup, because the download & upload speeds still sucked (port was properly forwarded, connection seems to be fine), but it's another problem
so i removed the patch, restored the original tcpip.sys, changed the torrent client to deluge and all the problems were vanished, i'm able to download/upload with full speed since then... so long story short, the patch has done its job
if you want to find out if your system is affected by this "problem", just check the system's event log if there's any event with ID 4226