If it is not in Windows Add/Remove Programs it has probably not installed itself as anything other than an extension in Chrome. If it will not allow itself to be disabled or uninstalled from Chrome I would be tempted to uninstall Chrome and start again.
And when I say uninstall Chrome I also mean to clear out its folders as well - that is, manually. You will lose saved passwords etc. but maybe that a price worth paying.
Uninstall Chrome using Add/Remove and choose get rid of profiles if asked.
Then go to Windows Explorer/My Computer. On the toolbar choose View>>>Options>>>View tab>>> tick Show hidden files and folders and untick Hide protected system files. Go to C:\ and the Users folder>>>Your profile>>>AppData>>>Roaming. in Roaming delete the Google folder. Go to Local. In Local delete the Google folder. Also go to Program Files and Program Files (x86) and delete any Google folder.
If you have CCleaner run it, or get it here:
http://www.piriform.com/ccleaner/download and run it, but make sure all the items in Chrome are ticked.
Go to Windows Explorer/My Computer and reverse all this: On the toolbar choose View>>>Options>>>View tab>>> tick Show hidden files and folders and untick Hide protected system files.
Reboot and reinstall a fresh copy of Chrome from
https://www.google.co.uk/intl/en_uk/chrome/browser/If you have lots of bookmarks you might want to export them before removing Chrome - they should be safe, but have a good look and delete any you do not recognise before exporting them.