Remove Ask from browser

http://support.mindspark.com/link/portal/30028/30031/Article/222/Toolbar-Removal-Instructions
http://www.bleepingcomputer.com/download/adwcleaner/
adwcleaner is one of the best

From your question, it is understood that you want to set Google.com as homepage on your web browser. Also, whenever you try to open your browser, you are getting Ask search.

For your information, Ask search is a kind of virus which infects your browser and changes browser settings without your knowledge. Hence, it is vital to remove it completely from your computer. To do this, the following link can be helpful:
http://malwaretips.com/blogs/remove-ask-toolbar-and-search/

Once you have removed Ask from your computer, you can set Google.com as you homepage by following the instructions mentioned on the following link:
https://support.google.com/websearch/answer/463?hl=en

GuruAid.com

Quite straight forward.go into control panel....click on program add remove near top of new window....wait for dropdown menu to complete then look for ASK and click remove.it is a browser add on usually part of an install package and very annoying.

Before you do anything, make sure all browsers are closed. Check the Task Manager to make sure none of the browsers are open. (Maybe you should print the directions out first, or use a different device to display this page)
Then, open up Control Panel and go to "Uninstall a program" (Add or Remove Programs if you are still on Windows XP). In the list of applications, find and uninstall Ask Toolbar Updater and Ask Toolbar. If you have already done this and you still have a problem, look for any applications in the list that has "Ask" in the Publisher field. With the software gone, the next step is to clean up the Web browser. The toolbar installed several browser extensions, changed your default homepage to nl.ask.com, and changed the default search engine to use Ask.com
Preferably use ccleaner to remove ask.com, then run a registry clean with ccleaner. Also, you might want to open up firefox, then tools>restart with add-ons disabled>reset click apply.
CCleaner Standard

Go to your browser setting; and in search option please set google in place of ASK.

Go to your control panel, program and features, browse for the ask toolbar and uninstall the toolbar. Reboot the computer after the uninstall. If you can't remove the app, follow the steps as per web link:
How to Remove the Ask com Toolbar From Your Browser

Here are good instructions on how to change your search engine from Ask.com to something else. You can find instructions for all the different web browsers here:

Why can remove the Ask default homepage from my browser

Go to Control panel /add/remove programs and remove "ASK" try resetting Browser settings

I tried to post this in Spanish for you, but the FixYa website won't allow it, so here's the English version:

How do I uninstall the Toolbar?

You can easily uninstall the Toolbar using the instructions below:

Windows XP:

1. Close all open Web browsers
2. From the "Start" menu in Windows, select "Control Panel"
3. Select "Add/Remove Programs"
4. Select the program with the Ask logo and the text "Ask Toolbar" (or our partner's brand for a custom Toolbar)
5. Click "Change/Remove"

Windows Vista:

1. Close all open Web browsers
2. From the "Start" menu in Windows, select "Control Panel". Under the "Programs" icon, select "Uninstall a program"
3. Select the program with the Ask logo and the text "Ask Toolbar" (or our partner's brand for a custom Toolbar)
4. Click "Uninstall" and then "Continue" to remove the Toolbar

Windows 7:

1. From your computer's 'Start' button, select 'Control Panel'
2. Click the "Uninstall a Program" option found under the "Programs" category
3. Select the program with the Ask logo and the text "Ask Toolbar" (or our partner's brand for a custom Toolbar)
4. Click 'Remove'

You can also uninstall the toolbar directly from the toolbar

1. Click on the chevron (down arrow) on the Option button on the toolbar
2. Select "Uninstall" from the drop down menu
3. Click "Yes" when asked "Are you sure you want to uninstall this product"
4. Close all open web browsers
5. Click "OK" on the popup window

We ask that once you have uninstalled the Ask Toolbar that you reboot your computer to ensure that the uninstall process is complete.