Visual Editor Not Working

My Issue:
The Visual option under Posts is not working and I am not able to get the Bold, Italics, etc. buttons to format my posts.
Also when I clicked “Screen Options” and selected “Number of Columns” as “1”, all the options went off from the right-side to below the text box. However, when I switched it back to “2” again the options never came back to the right-side; it stayed below the text box.

My current configuration in brief:
1. WordPress 3.2.1
2. PHP 5.2.17
3.SQL version 5.0.92-community
4. Theme “Mainstream” 1.7.1 Framework 4.0.0 from Woo themes (https://www.woothemes.com/2009/07/mainstream/)

Here’s a list of things that I had done to restore the Visual Editor for the last 5 days:

1. Disabled all the plugins by bulk.
2. Checked whether it’s disabled in my user’s profile. It’s not as the option ” Disable the visual editor when writing” is unchecked.
3. Re-installed the WP-admin and WP-includes folder as advised in the WordPress forums.
4. Tried to insert the line – Define(‘CONCATENATE_SCRIPTS’, false ); – in WP-config as advised at https://www.techiecorner.com/1656/wordpress-visual-editor-not-working/ and elsewhere. I kept getting an error whenever I tried doing so and couldn’t even login to the wordpress. So changed back to the original file and I could login again.
5. Reinstalled wordpress by clicking on “Re-install Now” from Dashboard -> Updates.
6. Checked on different browsers like Internet Explorer, Firefox and accesing the page on other computers.
7. Contacted my hosting provider to check the current PHP versions which they say is 5.2.17, which I think is fine. They can’t seem to solve the issue at their end.
8. Changed and tried theme Twenty Ten.

Nothing worked. However, I caught some errors in the WordPress -> Add New Post page (the place where the Visual Editor is supposed to be working) as delivered by the “Firebug” plugin in Firefox. Here are the 4 errors:

1. Syntax error: If(!v)window.addEventListener(‘load’,a…it:function(l){var m=’checkspell’,n=l. Ckedit…r=3.2.1 (line 159)
2.Missing ) after argument list: (function(d){var a=/^\s*|\s*$/g,e,c=”B…e_colors_title:j.getLang(“more_colors” Wp-tin…0110630 (line 1)
3.TinyMCE is not defined: TinyMCE.addI18n({en:{common:{edit_conf…tion:”Caption”,alt:”Alternate Text”}); Wp-LAN…0110630 (line 1)
4. Tinymce is not defined: Load_ext : function(URL,lang){var sl=…kDone(URL+’/langs/’+lang+’_dlg.js’);} Post-new.php (line 1019)

Now, I thought all these errors must be because of a corrupted WP-Included folder, where TinyMCE resides, as TinyMCE is responsible for the Visual Editor. However, inspite of reinstalling the WP-Includes folder and even the TinyMCE folder there, didn’t help.

Please help me resolve this as I am trying it for the last 5 days and making a post is so much difficult for me without the Visual Editor, as I don’t know HTML and other technicals much.

Thanks.