Debugging Drupal's White Screen of Death?

I have a Drupal installation that previously worked perfectly on my localhost. However, now, after a formatted my computer, it just shows a blank screen (completely white).

So my question is, how can I see where things are going wrong, if I can't even log into the sever?

The only errors I can find are (taken from the Apache Error Logs):

[Tue May 17 05:05:04 2011] [notice] Parent: child process exited with status 255 -- Restarting.
[Tue May 17 05:05:04 2011] [notice] Digest: generating secret for digest authentication ...
[Tue May 17 05:05:04 2011] [notice] Digest: done
[Tue May 17 05:05:07 2011] [notice] Apache/2.2.11 (Win32) DAV/2 mod_ssl/2.2.11 OpenSSL/0.9.8i PHP/5.2.9 configured -- resuming normal operations
[Tue May 17 05:05:07 2011] [notice] Server built: Dec 10 2008 00:10:06
[Tue May 17 05:05:07 2011] [notice] Parent: Created child process 6992

There are no errors in Watchdog...

I am using Xamp 1.7.1 (PHP 5.2) and Drupal 6.

I just also need to mention that once I try and load the site on my local machine, apache also crashes! I added this:

error_reporting(E_ALL);
ini_set('display_errors', TRUE);
ini_set('display_startup_errors', TRUE);

And it still just shows the screen of death? Where can I actually see errors?

I also found this in apache access.log:

127.0.0.1 - - [17/May/2011:05:22:14 +0200] "GET /greekmerchant/src/ HTTP/1.1" 200 3
127.0.0.1 - - [17/May/2011:05:25:45 +0200] "GET /greekmerchant/src/update.php HTTP/1.1" 302 -
127.0.0.1 - - [17/May/2011:05:25:46 +0200] "GET /greekmerchant/src/update.php?op=info HTTP/1.1" 200 -

... after trying to access update.php. It also just goes to a white screen.

I have this in my sql config file:

[mysqld]
port= 3306
socket= "C:/xampp/mysql/mysql.sock"
basedir="C:/xampp/mysql" 
tmpdir="C:/xampp/tmp" 
datadir="C:/xampp/mysql/data"
skip-locking
key_buffer = 1