Installing SilverStripe...
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 /home/websider/public_html/mysite/_config.php
Creating '.htaccess' file...
Creating /home/websider/public_html/.htaccess
Building database schema...
[Warning] Cookie 'alc_enc' can't be set. The site started outputting was content at line 656 in /home/websider/public_html/install.php
POST //install.php
Line 21 in /home/websider/public_html/sapphire/core/Cookie.php

Source
12     * @param name The variable name
13     * @param value The variable value. May be an array or object if you wish.
14     * @param expiryDays The expiry time, in days. Defaults to 90.
15     */
16    static function set($name, $value, $expiryDays = 90) {
17       if(!headers_sent($file, $line)) {
18          $expiry = $expiryDays > 0 ? time()+(86400*$expiryDays) : 0;
19          setcookie($name, $value, $expiry, Director::baseURL());
20       } else {
21          if(self::$report_errors) user_error("Cookie '$name' can't be set. The site started outputting was content at line $line in $file", E_USER_WARNING);
22       }
23       $_COOKIE[$name] = $value;
24    }
25    
26    /**
27     * Get a cookie variable

Trace
Cookie 'alc_enc' can't be set. The site started outputting was content at line 656 in /home/websider/public_html/install.php
Line 21 of Cookie.php
Cookie::set(alc_enc,1:96801e883a9d8dee5dff8fa592607d54)
Line 266 of Member.php
Member::autoLogin()
Line 399 of Member.php
Member::currentUser()
Line 149 of Folder.php
Folder->constructChild(SilverStripeLogo.png)
Line 107 of Folder.php
Folder->syncChildren()
Line 112 of Folder.php
Folder->syncChildren()
Line 107 of Filesystem.php
Filesystem::sync()
Line 811 of install.php
Installer->install(Array)
Line 123 of install.php

Can you please expound a little on your comment.

I upload all my files to the server.
Type in the domain name to begin installation.
The system defaults to the blackcandy theme.
Enter my details.
Click the button to install.

Do I install the system first using the tutorial?
Then if/when it fails, install the blackcandy? what should I do? Please explain more the steps you took to do this.

Thank you,
Steve

I should add that I have never installed with the tutorial before

i am having the EXACT same problem so please help. thanks

This is happening due to the value of the open_basedir being set in the php configuration.
This may be solved by editing the php.ini file, by changing the value of open_basedir or commenting it out.