You can't use your old .config directly but you can use it as a
reference when configuring your new kernel.
I went through the process of upgrading from a 2.4 to a 2.6 kernel on a
Gentoo system.
This is the guide I used and it should be informative whatever
distribution you use.
http://www.gentoo-linux.org/doc/en/migration-to-2.6.xml


----- Original message -----
From: "Shawn Fertch" <sfertch at gmail.com>
To: "TCLUG Mailing List" <tclug-list at mn-linux.org>
Date: Sat, 25 Mar 2006 14:32:41 -0600
Subject: [tclug-list] 2.4 to 2.6 kernel upgrade

When upgrading from a 2.4 to 2.6 kernel, can I use a .config file from
2.4?

Also, what would be the procedural steps to do the upgrade?

Can I do everything under the 2.4 kernel, or do I need to be in the 2.6?

Sad to say I've never done a kernel recompile or upgrade in all the
years
I've been using Linux....

--
-Shawn

-Nemo me impune lacessit.  Ne Obliviscaris..