Along with Vipul's post regarding:
"Please check your install media and make sure you have installed the web components"
.....you probably dont have IIS installed on the machine. Without IIS the Manager and Services Directory wont install. This would have been a warning that you could skip through during the AGS install.
You'll have to install IIS from ADD/Remove Programs > Windows Components
Then go back and do a either a modify OR a remove then re-install of AGS.
...and then of course there's the display problem which could be permissions like he said, or various other issues. However I'd get IIS working first, that may fix the second problem if its a simple display/virtual directory issue
