Newest daily build has a little more to say in the error message:
I am now running through the installation steps (this should take about 30 seconds)
If you receive a fatal error, refresh this page to continue the installation
# Creating 'mysite/_config.php'...
# Creating F:\xampp\htdocs\silverstripe\mysite/_config.php
# Creating '.htaccess' file...
# Creating F:\xampp\htdocs\silverstripe\.htaccess
# Building database schema...
# Checking mod_rewrite works...
# http://localhost/silverstripe/InstallerTest/testrewrite Rewrite is DirectorySlash On Order deny,allow Deny from all Allow from 127.0.0.1 RewriteEngine On RewriteBase /silverstripe RewriteCond %{REQUEST_URI} !(\.gif)|(\.jpg)|(\.png)|(\.css)|(\.js)|(\.php)$ RewriteCond %{REQUEST_URI} ^(.*)$ RewriteCond %{REQUEST_FILENAME} !-f RewriteRule .* F:/xampp/htdocs/sapphire/main.php?url=%1&%{QUERY_STRING} [L] Creating F:\xampp\htdocs\silverstripe\.htaccess
# http://localhost/silverstripe/InstallerTest/testrewriteERROR: mod_rewrite not working, redirecting to mod_rewrite test page
# Creating F:\xampp\htdocs\silverstripe\.htaccess
I will now try and direct you to rewritetest to troubleshoot mod_rewrite
DirectorySlash was Off before, i changed to On but same problem...