Change Max Concurrent Downloads in Regedit

Legacy web engines and components running on the Windows Internet (WinINet) API—such as Internet Explorer and embedded WebBrowser controls—enforce strict limits on the number of simultaneous connections allowed per web server. This article explains how to use the Windows Registry Editor (Regedit) to adjust and increase the maximum number of concurrent downloads and connections allowed by these legacy engines.

Step 1: Open the Windows Registry Editor

  1. Press Windows Key + R to open the Run dialog.
  2. Type regedit into the field and press Enter.
  3. Click Yes if prompted by User Account Control (UAC).

Step 2: Navigate to the Internet Settings Key

In the Registry Editor’s left sidebar, navigate to the following path:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings

(Note: To apply this limit to all users on the computer instead of just the current account, navigate to the same path under HKEY_LOCAL_MACHINE instead.)

Step 3: Create or Modify the Connection Values

Legacy engines differentiate between HTTP 1.1 and HTTP 1.0 servers, requiring two distinct DWORD values:

  1. Look for the value named MaxConnectionsPerServer (for HTTP 1.1). If it does not exist:
    • Right-click an empty area in the right pane.
    • Select New > DWORD (32-bit) Value.
    • Name it MaxConnectionsPerServer.
  2. Look for the value named MaxConnectionsPer1_0Server (for HTTP 1.0). If it does not exist:
    • Right-click an empty area in the right pane.
    • Select New > DWORD (32-bit) Value.
    • Name it MaxConnectionsPer1_0Server.

Step 4: Set the Maximum Connection Limits

  1. Double-click MaxConnectionsPerServer.
  2. Under Base, select the Decimal radio button.
  3. In the Value data field, enter the desired number of concurrent connections (e.g., 10 or 16).
  4. Click OK.
  5. Repeat the exact same process for MaxConnectionsPer1_0Server.

Step 5: Apply the Changes

Close the Registry Editor and restart your legacy browser or any application relying on the WinINet API to apply the new download and connection limits.