Internet Explorer complies with Internet standards (RFC 2068), so it limits by default the number of simultaneous downloads to two, plus a queued one.
Sometimes it comes in handy to have more than two downloads available.
The same registry tweak that worked in WinXP also works in Vista.
So...to increase the amount of downloads available in IE just accomplish the below reg tweak:
CODE Windows Registry Editor Version 5.00
;we enable more simultaneous downloads for IE to 20 (default is 2)
[HKEY_USERS\.DEFAULT\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"MaxConnectionsPerServer"=dword:00000014
"MaxConnectionsPer1_0Server"=dword:00000014
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"MaxConnectionsPerServer"=dword:00000014 "MaxConnectionsPer1_0Server"=dword:00000014
The above is set for 20 simultaneous downloads.