i get this error after installation
Fatal error: Maximum execution time of 60 seconds exceeded in C:\xampp\htdocs\silverstripe\sapphire\core\ManifestBuilder.php on line 458
Does anyone know how i can fix this?

Where does this occur? Any screenshots you could provide to give some context?

You can also force the execution time up by setting a few things at the top of mysite/_config.php _before_ starting the installation:

ini_set('max_execution_time', 300);
set_time_limit(300);

After trying to reinstall the is the error message i get:
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

Setting up 'mysite/_config.php'...
Setting up C:\xampp\htdocs\silverstripe\mysite/_config.php
Setting up '.htaccess' file...
Setting up C:\xampp\htdocs\silverstripe\.htaccess
Building database schema...

[Warning] date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Europe/Paris' for '1.0/no DST' instead
POST /silverstripe/install.php

Line 89 in C:\xampp\htdocs\silverstripe\sapphire\core\model\fieldtypes\Datetime.php
Source

80 * Returns either the current system date as determined
81 * by date(), or a mocked date through {@link set_mock_now()}.
82 *
83 * @return SS_Datetime
84 */
85 static function now() {
86 if(self::$mock_now) {
87 return self::$mock_now;
88 } else {
89 return DBField::create('SS_Datetime', date('Y-m-d H:i:s'));
90 }
91 }
92
93 /**
94 * Mock the system date temporarily, which is useful for time-based unit testing.
95 * Use {@link clear_mock_now()} to revert to the current system date.
Trace

date(Y-m-d H:i:s)
Line 89 of Datetime.php
SS_Datetime::now()
Line 1023 of DataObject.php
DataObject->write()
Line 1297 of SiteTree.php
SiteTree->requireDefaultRecords()
Line 231 of DatabaseAdmin.php
DatabaseAdmin->doBuild(1)
Line 1026 of install.php
Installer->install(Array)
Line 190 of install.php

Open up your php.ini file (in C:\xampp somewhere) and look for date.timezone and make it look like this:

date.timezone = Europe/Paris

This is a setting which should always be set in PHP and is therefore not a SilverStripe issue.

Sean

ok. will do that now and get back to you.

You can refer to http://php.net/manual/en/timezones.php if you're not sure which timezone should be set.

same error message. i restarted server... did everything. but same problem

What did you set the date.timezone setting as?