Installing Drupal

Hi,

I have a problem when i attempt to install drupal 7 in a subfolder of my website : www.mywebsite.com/subfolder/-drupal installation-
The relative url of the first page's form begin by a slashe: "/install.php", so when i click on "save and continue" i'm redirected to www.mywebsite.com/install.php and i get a 404 error.
Someone get an idea?
(scuse me for my bad english: i'm french)

When i try to install Drupal 7 i get this error:

(SQLSTATE[HY000]: General error: 2006 MySQL server has gone away)

Versions:
PHP 5.2.13

[...]
max_execution_time =60
memory_limit=128M
[...]

MySQL 5.0.90 (mysql, not mysqli, not innodb)

I modified my MySQL as followed but doesnt help:

I've never used Drupal before, and want to install it on my development computer to try it out. I keep getting this error during installation, though. After setting up the database, I get this:

In Drupal 6, there was an option to enable file attachments. In Drupal 7 they changed things up and I'm totally lost.

I want users to be able to upload files in my forums.

I created a forum called General. I want people who come to be able to upload pictures or documents. I was successful with Drupal 6 but cannot figure it out in 7. Can anyone help?

I am trying to set up a D7 test installation. To learn before I do any actual conversions - I have maybe 10 accounts running on D6 (done over a couple years). So, while I am not a hotshot, I do know my way around a little...

Usually i install a new D6 system by allowing Fantastico to install on my (public) server. Piece of cake...

I have tried to install D7 two ways:

1) Download D7 from Drupal and follow directions and 2) Create 6.19 D6, get it going, then run D7 conversion from local.

Hello,

can I use newest PHP 5.3 with drupal?
I've got installed 5.2x already, but imho they've released new 5.3 now.

TY