[TYPO3-english] Can't move installation

[colin taylor]

I have extracted the zip file in my root directory. Changed all permissions and installed with database etc. 
Trouble is, I can only use this structure:
 "h ttp://mydomain.info/introductionpackage -6.1.5/"
When I move from intodructionpackage -6.1.5 directory to the root directory, I get:

Warning: require(SystemEnvironmentBuilder.php) [function.require]: failed to open stream: No such file or directory in /home/content/48/8529948/html/count/introductionpackage-6.1.5/typo3/sysext/core/Classes/Core/Bootstrap.php on line 32

Fatal error: require() [function.require]: Failed opening required 'SystemEnvironmentBuilder.php' (include_path='.:/usr/local/php5_3/lib/php') in /home/content/48/8529948/html/count/introductionpackage-6.1.5/typo3/sysext/core/Classes/Core/Bootstrap.php on line 32

What is going on?
Please help.