Been fighting with this issue myself today and seem to have resolved it by doing the following:

 In VS2005 -

   1. Click Website on the menu

    2. Click Start Options...

    3. Click Start Options on the hierarchy to the left

    4. Click "Use default web server" under the Server section EVEN if it is already selected. The Apply button should become enabled.

    5. Click Apply

    6. Click OK

    7. Try running / debugging your site again.

    May not work for you, but it worked for me thankfully. I'm guessing something just went screwy in the settings. Most likely for me it was Office 2007 trial install that caused the issue.

    Hope this helps anyone else who stumbles upon this post. 

hi all,

  am very new to this webdesig.. i have gone through all the post in this forum.. but my problem is different am able to run my project in my system after deploying in iis (my os xp sp 2 and iis 5.1) but whn am browsing from ip of my system i.e(http://192.168.9.152/website1/main.aspx) in lan cannection am geeting page cant be displayed error.. but if am using the samething in my system am able to view my page.
can  anyone tell me wat can be the error... and am disabling my proxy seeting whn am running in my system.. and i have run this cmd (netsat -a) response i got as follows

can anyone tell me wat should i do.. i have read in some forum if am using xp not more than 10 ppl will be able to access my website.. but tat ok.. 
and  also i  have attached this code in webconfig file..

  <system.net>
<defaultProxy>
<proxy bypassonlocal="False" usesystemdefault="False" />
</defaultProxy>
</system.net>
can any tell me wat i have missed out..

hi all,

  it's true tat some time ur Brain became so dump tat ull not even know silly things...... tats wat happened with me i was pulling my hairs and struggling  hard .. but the solution was so simple .. i has enabled by firewall but  i had not checked webserver (HTTP)  ..

i thougth this will be helpfull to ppl like me ..who is very new to webdesg..

start-> Controlpanal-> windowsFirewall->  (click On) -->Advancetab-->seetings--> webserver (http) just click tat and enable port 80 it's done...

Hi I am also getting the same error. On before that i'm getting one more error also. That is..

ASP.Net Developement Server failed to start to listening on part 1201.

Error Message.

Only one  usage of each socket address(protocol/network address/port) is normally Permitted"

Please guide me to fix this problem.

Hi Folks,

I fixed this problem by adding the port entry by opeing the solution in Notepad and add it. 

VWDPort = "3000"
VWDDynamicPort = "false" 

That is it. The problem got solved this way.

nvm

 thank you so much.

I checked and found that my port 80 was somehow blocked or inactive and got the IIS6 resource kit to run TinyGet and clear that up. At the same time i cleared any programs that might have affected these VS 2k5 process and removed them completly from my Firewall list even if they were on and my anti virus firewall "allow". Then i disabled them both before i ran VS2k5 and Visual Studio ran without giving me this blasted error.

 Special thanks to danmor!