This article is to focus on using GNS3 on Vista x64 with Microsoft Telnet. (Best viewed using IE 7 and above)

1. First of all download the required setup files for installation of GNS3 from:
   GNS3 v0.6 all-in-one (includes Dynamips, Pemu and WinPCAP 4.0.2)
   or
   GNS3 v0.6 zip
   WinPcap 4.0.2 auto-installer (driver +DLLs)
   0.2.8-RC2 binaries for Windows (2000 and XP)
2. For convenient sake i use GNS3 v0.6 all-in-one setup files.
   
3. Just execute the setup file and the UAC will be prompt just click Allow.
4. The setup wizard will appear just follow the installations. (Pls refer to the pix below.)
5. Under the preference (General) change Terminal Command to “Telnet.exe %h %p”. For putty user, you can specified to use putty as well and any similar software.
6. Under the preference (Dynamips) change Executable Path “C:\Program Files (x86)\GNS3\Dynamips\dynamips-wxp.exe” and click Test button. Ensure Dynamips successfully started and then click Ok.
7. Return to Setup wizard click on Step2
8. Browse for the IOS. (IOS can be downloaded from Cisco using the CCO account)
9. Enable Telnet Client and Server for Windows Vista, click , then Start Search type Optionalfeatures.exe and press Enter.
10. Tick Telnet Client (Telnet Server not required) and click OK.
11. Finally copy telnet from C:\Windows\System32\telnet.exe into C:\Program Files(x86)\GNS3 folder