Need help with updating .htaccess for wordpress URLs

I am trying to give me wordpress blog SE friendly URLS. However the admin tells me that i need to update my htaccess. It provides me some code to add to my htacces file.

After i add the code it still doesnt work. I appreciate any help. Here is the code it tells me to add:

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /blog/
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /blog/index.php [L]
</IfModule>

Code (markup):

here is the code that is already present in my htaccess file:

# -FrontPage-

IndexIgnore .htaccess */.??* *~ *# */HEADER* */README* */_vti*

<Limit GET POST>
order deny,allow
deny from all
allow from all
</Limit>
<Limit 

PUT DELETE>
order deny,allow
deny from all
</Limit>
AuthName www.custom-website-designs.net
AuthUserFile /home/customw/public_html/_vti_pvt/service.pwd
AuthGroupFile /home/customw/public_html/_vti_pvt/service.grp
AddType text/html .shtml .shtm .htm .html
AddHandler server-parsed .shtml .shtm .htm .html
ErrorDocument 401 /index.html
ErrorDocument 404 /index.html
ErrorDocument 405 /index.html
ErrorDocument 500 /index.html

Code (markup):

 

Here's what I had to put into my .htaccess to enable pretty URL's for WordPress:

RewriteEngine On
RewriteBase /
RewriteRule ^category/(.*)/(feed|rdf|rss|rss2|atom)/?$ /wp-feed.php?category_name=$1&feed=$2 [QSA]
RewriteRule ^category/?(.*) /index.php?category_name=$1 [QSA]
RewriteRule ^author/(.*)/(feed|rdf|rss|rss2|atom)/?$ /wp-feed.php?author_name=$1&feed=$2 [QSA]
RewriteRule ^author/?(.*) /index.php?author_name=$1 [QSA]
RewriteRule ^([_0-9a-z-]+).htm([0-9]+)?/?$ /index.php?name=$1&page=$2 [QSA]
RewriteRule ^([_0-9a-z-]+).htm/(feed|rdf|rss|rss2|atom)/?$ /wp-feed.php?name=$1&feed=$2 [QSA]
RewriteRule ^([_0-9a-z-]+).htm/trackback/?$ /wp-trackback.php?name=$1 [QSA]
RewriteRule ^feed/?([_0-9a-z-]+)?/?$ /wp-feed.php?feed=$1 [QSA]
RewriteRule ^comments/feed/?([_0-9a-z-]+)?/?$ /wp-feed.php?feed=$1&withcomments=1 [QSA]

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

Code (markup):

Plus, in the Wordpress admin console, under Options and then under Permalinks, I had to set my customer permalink structure to "/%postname%.html"

 

thanks ill give that a try.