I have a Dell Dimension 2400 1GB ram OS Ubunut12.04.

Yesterday it was working OK.

I think there was an update from Ubuntu this morning.

Today Very Very slow.

If I disconnected internet it was still slow.

System Monitor did not show much, but 45% of memory was in use and I was only run system monitor....I know there are other program's that running in the background.

Help Please

it maybe defrag

It will be interesting to see how you suggest he defrags his Linux system. If he is using a journalling file system like ext4 which is the default on most distros it is extremely unlikely that defraging is required.

You say it has started being slow since an update, did that update include ureadahead by any chance? or anything to cause ureadahead to reprofile the start up sequence? When I was using Ubuntu and an update did this 99% of the time this was the cause and it crippled my low powered laptop. After about an hour of running reboot your machine and see how it goes.

Just when you think you heard it all.

Have you tried restarting the computer? You should look at the proccess area in system monitor and see how much of your RAM and CPU certain proccesses are taking up. Did you have backups?

Unless your RAM and CPU are at 100%, that wouldn't be the cause of a slow computer. I'd suggest a reboot before anything else.

A reboot can't hurt, especially if the system is doing a lot of swapping. Swapping can slow down responsiveness.

1GB RAM is not much for Ubuntu with the standard Ubuntu desktop, which is extremely resource hungry. For testing purposes, you could install a light-weight window manager (I'd suggest Fluxbox, as opposed to a desktop environment like XFCE or LMDE) and see whether you notice an improvement; it's in the repos.

You might also get something like GKrellM or Conky to be able to easily keep an eye on swap.

I have a computer with similar specs running Slackware Current; it's noticeably slower (but not unbearable) with KDE. It runs fine with Fluxbox or E17, but I notice that, even then, big apps, such as the GIMP and LibreOffice, take longer to start up than on my brawnier boxes.

(Note that Fluxbox is extremely plain out of the box, though it could be configured up to be quite pleasing, but I think it's a good tool for this test. Full disclosure: I'm a Fluxbox fanboy.)

I have pretty much an identical system. It has Ubuntu 12.04 with the XFCE and LXDE desktops. They both work well with 1GB, I wouldn't call them "slow" by any means.

I second that. In fact, I would strongly recommend doing a clean install of Lubuntu: http://lubuntu.net/
Doing a clean install would be the fastest and the easiest way to set up a fast and light system on a slow computer.

I currently have Lubuntu 12.10 running on an Acer 3680 laptop with a 1.6GHz Celeron and 1.5 GB memory and it runs quite well.
If you plan on using that system for a while longer, it would be beneficial to add another gig of memory, assuming that the system's BIOS can use it.

Today my PC is working normally ! ? *

What happen as follows:- The mouse would sometimes (but not all the time) be slow or slower, but when I clicked to close a program/app nothing happen at all.

1/ I log in as guest and my PC seamed to work normally, was able to stream 3 prog's from BBC on catchup.

2/ I log out as guest and back in as me (Richard) with system Password.

3/ As it was late desired to close down the PC for the night......but it would not....kept Restarting.....so I held the start button on PC until it switch OFF .....

4/ Today I ran terminal and typed .... sudo apt-get update ..... since then it has worked normally.

Any comment ?

There are so many possibilities I can't guess.

If it starts to happen again, open a terminal and run top to see what is using the memory. See man top for details. Maybe take a screen shot or pipe the output to a file.

If it gets worse, repeat, maybe several times, so you can collect some historical data. Then post back here and we'll be happy to help identify the culprit.

Thank you Frank....I will look at that.

This morning I could not log in with system PW and had to reboot then OK.

Richard