If you experience a problem using the DebianInstaller, please first check:
the errata (either the errata of Debian/Stable D-I
or the errata of DI Development version)
and DebianInstaller/FAQ for your problem.
If the problem is related to the particular hardware you have, try DebianInstaller/Workarounds.
If you still have a problem, please send us an installation report using the template and a developer will get in touch with you. Please answer as many questions on the installation report as possible.