I use a sub-domain instead eg
almost all host providers let you have a subdomain for free
Install wordpress on the subdomain.
Copy across wp-content - that'll get your themes, plugins, and uploads such as images
Then export and import you MySQL database
Then use the following code in the sql bit of php-myadmin on your sub-domain
UPDATE wp_options SET option_value = 'http://backup.drummerscool.com' WHERE option_name IN ('siteurl', 'home')
This changes the database to point to your sub-domain
Then on the sub-domain install the velvet blues plugin, this lets you change all the posts/pages, images etc. point to the new sub-domain.
Finally in dashboard>settings>reading change the search engine visibility to discourage search engines from indexing your test site.
You now have a backup/test site !
To keep mine up to date each month I do the following :
Copy from main site to sub-domain the lastest uploads directory - that gets any images etc. across
Export/import the database
Do the UPDATE bit above
Do the velvet blues update
dashboard>settings>reading change the search engine visibility to discourage search engines from indexing your test site.
quick and easy !