Is this a wamp server?
If 'Yes' then you will need to extend the max-execution time in wamp\alias\phpmyadmin.conf in the line 'php_admin_value max_execution_time ***
Mine is set to 720 which works for me.

I would also advise you to change the MySQL myini file (from the wamp menu in the desktop icon) and near the bottom of the file to something like I have, thus..
innodb_buffer_pool_size = 2048M
; Set .._log_file_size to 25 % of buffer pool size
innodb_log_file_size = 512M
innodb_log_buffer_size = 32M
innodb_flush_log_at_trx_commit = 0

Explanation is InnoDB tables require a lot more hardware resources to be available to them, the older MyISAM tables are less demanding and execute faster, but these table structures are being phased out in favour of others like InnoDB..

Could also be a table name capitalisation problem.

Weyboat - thanks for the information. I didn't have wamp installed, but do now, and have set configs as suggested, but installation still failing at the 'while you wait' page. Botton left of page says 'An error has occured', and the page fills with lins of red script. First line is:
(vti_encoding:SR|utf8-nl vti_timelastmodified:TR|14 Dec 2016 03:55:58 -0000 vti_extenderversion:SR|12.0.0.0 vti_author:SR|Dell_XPS870\\Chris )

What does Gondwana mean by a capitalisation error?

By default the MySQL database will be created with all lower case table names..
This will not work for a Concrete install.
To get a concrete database working you need to go into the MySQL my.ini file and at the bottom of the file you will see this [mysqld] immediately after that put this line of code in.
lower_case_table_names = 2

So, it will look like this.
[mysqld]
lower_case_table_names = 2

Save the file, exit from wamp and restart it,,

One more thing...
Wamp 32 bit is much more stable than the 64 bit version!

Changes made, but still no success. The database is created, but that is as far as it gets before crashing. The screen is filled with a recurring code:

[Dec 2016 03:56:07 -0000 vti_extenderversion:SR|12.0.0.0 vti_author:SR|Dell_XPS870\\Chris vti_modifiedby:SR|Dell_XPS870\\Chris vti_timecreated:TR|14 Dec 2016 03:56:07 -0000 vti_cacheddtm:TX|14 Dec 2016 03:56:07 -0000 vti_filesize:IR|510 vti_cachedneedsrewrite:BR|false vti_cachedhasbots:BR|false vti_cachedhastheme:BR|false vti_cachedhasborder:BR|false vti_charset:SR|utf-8 vti_backlinkinfo:VX| vti_encoding:SR|utf8-nl vti_timelastmodified:TR|14 ]

These lines are repeated until the installation stops.

Can anyone help me with this one, or do I give up on C5?

I have dozens of perfect installs locally. I only use MAMP: http://www.mamp.info

Hi Steevb, thanks for replying. What version of C5 do you use?

Problem solved - I have deleted Concrete5 v8.0.3 and installed version 5.7.5.13. Worked perfectly.

This makes me think that the issue was php extensions. I fancy that c5 8 requires more than c5 7. If so, it would be good if an exhaustive list of php extensions required/desired were listed in the 'requirements' page, and for the c5 installer to check for them before dying.