WordPress upgrade taking 2 hours so far

Time to pull the plug. Afterwards if you can get to the dashboard try to update from there.

Well, you have to cut bait sometime as something has gone wrong. Close the browser to end the session. Then, if you can still get to the dashboard try to upgrade wp again.

If you can’t there are different ways to proceed. Here are some options for updating, http://codex.ww.wp.xz.cn/Updating_WordPress

These were the magic words!

I have a backup of the database.

Replace also all files in wp root directory.

No. Do not replace the wp-config.php file or the htaccess.