Usually I am working with Ubuntu linux on new laptops.
This works fine and comfortable.

On old laptops current Ubuntu releases need too much memory and slow down terribly.
Which of the linux versions is best for old laptops?
I still want to use them with a current release because of security updates.

Linux Lite isn't bad. Ubuntu based and runs the xfce desktop. The developer has made a lot of really nice choices in that distro. https://www.linuxliteos.com/ They have forums at linuxdistrocommunity.com/forums

antix is another nice one. runs a windowmanager rather than a full desktop, but its setup so well you'll hardly notice. based on debian, so you should be good on security updates for quite some time. Antix runs on my 900mhz laptop with 512mb of ram just fine, my eeepc atom processor just fine, and my modern HP laptop with a core i5 and 4gb of ram. antix.mepis.org. antix.freeforums.org.

Easiest way would be to just use Xubuntu or Lubuntu, they are significantly lighter then Ubuntu, but are still from the Ubuntu family, so that you will still be very used to the system and maintaining them is easier.

Thanks for your fast answers. I will try what you suggested.

Also uses xubuntu for older computers, and it runs fine on 2gig of ram.
Perfekt for home or office use eaven a small server.

Bridge LXDE is very light on resources
see review http://mylinuxexplore.blogspot.co.uk...-arch-bit.html

Archbang is also very light

In addition, see this site and jacook's post and TinyCore; things haven't changed a helluvalot since 2006 -- DEs (LXDE is the lightest) have just gotten bigger, it seems, including XFCE.

No DE just a WM as in dolpin_oracle's suggestion of antiX is the way to go for lighter RAM usage.

Peppermint is low on resources.
You should also during install create a large swap partition.

Slitaz gets updated once in a while but not daily.

Just saw a distro based on OpenBSD from Japan that was supposed to be pretty lightweight too.

If we knew more about the laptop we might get a better guess.

>
Thanks for your suggestions.

It's a Dell Latitude D800 with 1 GByte of Ram?

the 32 bit antix will run in less than 250mb, with icweasel/firefox running.

That's not all that low on RAM. You could run just about anything on that amount of RAM, but the Apps that you run are also an issue. If you run '1G's worth of apps' there isn't much that the OS will do to reduce that, so you have to either run lighter apps or fewer of them (or, with browsers, etc, keep the number of excess tabs and windows down to a reasonable number).

What you should do even if you have 512 mb of ram or 1gig is to create a larger swap partition then default 5-10 gig i good enough.

If you are used to ubuntu, then lubuntu or xubuntu are good choices. The biggest source of lag in ubuntu is the unity desktop, and not so much the underneath stuff. I've got a laptop that doesn't get along real well with ubuntu but gets along fine with xubuntu.

I'm running debian wheezy / stable on an old dell inspiron 1150. And atm using 108MB of 512MB of RAM. With iceweasel (firefox) on this page as I type.