A couple of things look out of place.
$Config['UserFilesPath'] = 'C:/wamp/www/website/imgs/' ;
This attribute is not an absolute path but rather it needs to be set relative to the document root... so if your site is in the "website" folder, this setting should look like this:
$Config['UserFilesPath'] = '/imgs/' ;
The second - which you can fill if you prefer to specify the absolute path - is not always necessary... in fact, I would leave it blank like this:
$Config['UserFilesAbsolutePath'] = '' ;
Then, make sure you have the permissions set on the folder "imgs". Even if it is on a testing server, you will have to be sure to CHMOD probably to 755 at least - maybe even 777.
Once you do that, you should be good to go.