We have an Acer Aspire One (Intel Atom with 1GB RAM) which was running Windows XP. Since it is no longer supported by MS I've spent some time to find a replacement.

For this hardware MS has no viable alternative I know of. There are, however, several Linux distributions that aim old netbook hardware.

I've checked these:

• Lubuntu: Ubuntu with LXDE
• Bodhi: based on Ubuntu
• Manjaro: based on Arch Linux, rolling release
• Peppermint: a Lubuntu variant
• Quelitu: aims to be the most resource-friendly
• Zorin: Ubuntu based with Windows-like user interface, it has several flavours

After some preliminary selection I decided to try Lubuntu, the official Ubuntu distro with LXDE window manager.

Lubuntu on Acer D250

I've used Lubuntu 14.04 for a couple of weeks but it turned out that there were a few showstoppers.

The installation went smoothly, it looks pretty, and it has a huge selection of applications.

There are, however some serious bugs. First of all, the wireless networkmanager applet simply does not work. Then the file manager has a very disturbing "feature": sometimes you have to click three times to switch to a folder. I could not figure out the "pattern" nor the cause or fix. There were some other minor annoyances.

Connecting to a new wireless network was a pain. It required knowledge of the underlying software and starting nm-applet with superuser privileges.

This was the point when I dropped all ubuntu variants (there are a lot of them).

Manjaro Linux

You can read about it's features on this page. It has several official flavours (XFCE, Openbox, KDE, etc.) and community editions including one optimized for Netbooks. I really liked UI layout of the Netbook edition. It fits almost perfectly the low resolution landscape display of the netbook so I gave this distro a try.

It starts a bit slowly and the auto-maximize feature is pointless sometimes but that's all on the down side.
The xfwm4-tileless window manager makes wonders on small screens. Everything I've tried worked out of the box. The software repo might not be as big as on Ubuntu but it still has a very good selection of apps. Since the dockbar is on the left and windows have no title when maximized the usable part of the interface is very big in comparison to other distros and Windows XP. Video playback was the best among the tested operating systems. No lags, no slugginess.

Manjaro Linux Netbook Edition is a stable, easy-to-use system which is also suitable to novice, non-Linux users (excluding the initial settings). It's even pretty (well, don't expect fancy gui effects), and it squeezes out all what your netbook can provide. You should really give it a try.

Others to mention

Gnome3 is my favourite desktop so I tried it but it was unusable. It simply requires more resources.

Most distros had problem with the low screen resolution. It was very common, that I could not click the OK/CANCEL buttons because they were out of my reach below the visible desktop.