Make sure you back up your registry first.
Take a minute to follow these directions before proceeding any further. Once your registry has been backed up we can begin.

As with most modifications, you should make sure that no other applications are running, especially Internet Explorer. Now, by following the simple procedure outlined below, you'll be able to increase your number of simultaneous downloads from 2 to 10.

Click on the Start button and select Run

On the Run line type Regedt32.exe and hit Enter. This will launch the Registry Editor

Locate the following key in the registry:
HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionInternet Settings
Click on the Internet Settings Key. Now go to the Edit menu, point to NEW, and click DWORD Value

Type MaxConnectionsPer1_0Server for the name of this DWORD Value

Double-click on the MaxConnectionsPer1_0Server key you just created and enter the following information:

Value data: 10.
Base: Decimal.

When finished press OK

Repeat steps 4 and 5. This time name the key MaxConnectionsPerServer and assign it the same values as indicated in Steps 6

Close the Registry Editor
That's all there is to it! If you modified your registry settings correctly, you should now have the capability to download up to 10 files simultaneously.