.htaccess with xampp at windows

[dimis283]

I use this code for .htaccess for a RewriteRule.
When I set in comments the

[#]RewriteBase /paul-mccartney

the rewrite wule is working.
What is wrong?

# BEGIN Gruppo Modulo Rewrite

<IfModule mod_rewrite.c>
RewriteEngine on
# Change following path
RewriteBase /paul-mccartney
RewriteRule ^([A-Za-z0-9-]+)/?$ single.php?slug=$1 [L]
</IfModule>

# END Gruppo Modulo Rewrite