Effect duration of robots.txt file.

[innofidelity]

in my web site there is demo site in that also, index in Google but no need it now.so i have created robots file and upload to server yesterday.in the demo folder there are some html files,and i wanna remove all these in demo file from Google.but still in web master tools it showing

User-agent: *
Disallow: /demo/

How long this will take to remove from Google ?

And are there any alternative way doing that ?

[AJPro]

Hello,

The robots directive will only prevent google from crawling the pages. In order t remove the pages from index you need to add "meta noindex" to the pages you want to have removed.

<meta name="robots" content="noindex">

http://support.google.com/webmasters/bin/answer.py?hl=en&answer=93710

[josh-riley]

And, if they are already indexed, you have to wait for them to be recrawled, then fall out of index, so it's not an immediate thing. Sometimes it takes days, sometimes weeks.

[KeriMorgret]

Google Webmaster Tools also has a remove URL function where you can remove an entire directory, which may be of help to you.