Problem: It is very slow when you try to access the remote computer using Remote Desktop Connection (RDP) in Vista operating system.
Disable TCP Auto-Tuning and Receive-Side Scaling State.
Step 1: Go to Start > Programs > Accessories. Right click “Command Prompt” and choose “Run as administrator”.
Step 2: Type the following command and press Enter:
C:\>netsh interface tcp set global rss=disabled
C:\>netsh interface tcp set global autotuninglevel=disabled
Step 3: Reboot the computer