Q: I can't open safari after downloading yosimite

1.  Use  free  AdwareMedic by clicking “Download ” from here

     http://www.adwaremedic.com/index.php

     Install , open,  and run it by clicking “Scan for Adware” button   to remove adware.

     Once done, quit AdwareMedic by clicking AdwareMedic in the menu bar and selecting

    “Quit AdwareMedic”.

  2. Safari > Preferences > Extensions

    Turn those off and relaunch Safari again.

    Turn those on one by one and test.

               or

    Remove the adware  manually  by following the “HowTo” from Apple.

    “Remove Genieo, also known as InstallMac”

    http://support.apple.com/en-us/HT203987

It does not appear that you read the links provided.

"               or

    Remove the adware  manually  by following the “HowTo” from Apple.

    “Remove Genieo, also known as InstallMac”

    http://support.apple.com/en-us/HT203987  "

If you do not have a browser available, please try the manual method given.

Remove Genieo manually:

http://support.apple.com/en-us/HT203987

First follow these steps to stop the Genieo or InstallMac processes, if they're running. Be particularly careful to restart your Mac when instructed.

1. Open the Activity Monitor app:
   You can use Spotlight (Command-Space) to search for "Activity Monitor," then choose Activity Monitor from the search results.
2. In the Activity Monitor window, click the CPU tab, then click Process Name at the top of that column to sort the list alphabetically.
3. Look for the process "Genieo." Select it, then click the Force Quit button in the upper-left corner of the window.
4. Look for the process "InstallMac." Select it, then click the Force Quit button.
5. Quit Activity Monitor.
6. From the Finder, choose Go > Go to Folder.
7. Type /private/etc/launchd.conf in the text field, then press Return.
8. If the file is on your Mac, a window opens with the file you searched for already selected. Drag the file to the Trash.

Restart your Mac, then continue to the next steps, below.Remove the files related to Genieo:

1. Select each item in the list below, starting with /Applications/Genieo.
2. Choose Edit > Copy.
3. From the Finder, choose Go > Go to Folder.
4. Choose Edit > Paste to paste the line you copied into the text field, then press Return.
5. If the file is on your Mac, a window opens with the file you searched for already selected. Drag the file to the Trash.

Repeat the steps above for each item in the following list. If you get a message that the folder can't be found, continue to the next item in the list./Applications/Genieo

/Applications/InstallMac/Applications/Uninstall Genieo

/Applications/Uninstall IM Completer.app~/Library/LaunchAgents/com.genieo.completer.download.plist

~/Library/LaunchAgents/com.genieo.completer.update.plist/Library/LaunchAgents/com.genieoinnovation.macextension.plist

/Library/LaunchAgents/com.genieoinnovation.macextension.client.plist/Library/LaunchAgents/com.genieo.engine.plist

/Library/LaunchAgents/com.genieo.completer.update.plist~/Library/LaunchAgents/com.genieo.completer.ltvbit.plist

/Library/LaunchDaemons/com.genieoinnovation.macextension.client.plist/Library/PrivilegedHelperTools/com.genieoinnovation.macextension.client

/usr/lib/libgenkit.dylib/usr/lib/libgenkitsa.dylib

/usr/lib/libimckit.dylib/usr/lib/libimckitsa.dylib

~/Library/Preferences/com.apple.genieo.global.settings.plist~/Library/SavedState/com.genieo.RemoveGenieoMac.savedState

Now do the same for each folder in the following list. When these folders open, no file will be selected. Instead, select all items (Command-A) in the folder and drag them all to the Trash.~/Library/Application Support/Genieo/

~/Library/Application Support/com.genieoinnovation.Installer/~/Library/Saved Application State/com.genieo.RemoveGenieoMac.savedState/

Restart your Mac, then continue to the next steps, below.

1. From the Finder, choose Go > Go to Folder.
2. Type /Library/Frameworks/GenieoExtra.framework in the text field, then press Return.
3. If the file is on your Mac, a window opens with the file you searched for already selected. Drag the file to the Trash.

Restart your Mac, then choose Finder > Empty Trash to permanently remove the files.