At the moment I have downstairs PC and an upstairs PC both connected to internet via WIFI. Neither connected to each other.
Getting more paranoid about not backing up either.
What I would like to do is buy an external hard drive, plugged in to downstairs PC, and have upstair PC back up documents to it. Down runs win7 upstairs XP.

Is this as simple as mapping a network drive and getting windows backup to backup to it? I havent a clue.

Western Electrical and Sandisk both do HDD with wifi for auto backup. The Go-Flex drives also have a free iPhone app that allows you to both back-up and access the drive remotely, your own private iCloud, if you will.
Up to 3Tb for around £150-170. I paid £200 for a 1Gb CF card back in ’03; shows how things have progressed.

Do they now.. That’s very clever. So not even attached to either pcs just remote access?

Cheers I’ll look into that.

You can spend a fair bit less, and just plug an external HD into each computer once a week. But must admit, I’m interested in the whole wi-fi aspect. Wouldn’t that involve compressing files and losing info (photos…).

If it’s not automated I fear i won’t do it..

Dropbox. They will back-up to each other via wifi and create a copy on-line. Fully automated. The free version is initially limited to a couple of Gb so not ideal for photos if you take hundreds but those are easy to do manually.

You get extra free space by sharing links like this one {Dropbox referral for extra free space} or you can buy more

+1 for Dropbox – just syncs everything to the cloud in the background, works really well.

NAS device. Plug it into your router – full access to any device on the network.

Dropbox is nice, but it’ll kill your bandwidth if syncing a large number of files – plus you’ll probably eat up the allowance fairly quickly.

My Internet is sub 1mb speed so online is a prob

Well the 100G dropbox is $19.99 a month, however, I’d assume most people have more than 50G of data on a machine, especially if you want to backup the whole thing – so you’d probably need to go for their custom data plan to be able to accommodate both machines.

Alternatively, if you needs lots of space you could look into using Amazon S3. But I still think a NAS device is the easiest, most cost efficient route.

Dropbox works in the background so it only uses ‘spare’ bandwidth. You can set limits so it won’t throttle even the slowest internet. Having a back-up on-line is a big plus for lots of reasons.

http://www.buffalo-technology.de/products/network-storage/linkstation/ls-wxl-linkstation-duo/

I believe it comes with software so you can schedule backups to happen automatically.

Well the 100G dropbox is $19.99 a month, however, I’d assume most people have more than 50G of data on a machine, especially if you want to backup the whole thing

I wouldn’t use it to back up a whole machine. I use it for all my work stuff (3D CAD, photoshop, etc) and other important documents. Basically stuff that is live and changing. For that my 10Gb free is plenty. Photos, videos and music which only need backing up once go on a couple of USB drives, but a NAS would probably be better. Basically I think you need both 🙂

When you say not connected to each other, are they on the same WiFi network?

If you have drive space, you could just make sure they are on the same workgroup, set up a shared folder on each machine and back one up to the other over the local network.

What about your router? Some of them allow you to plug in an external USB drive and access it over the network, which would give you central storage accessible from both machines.

A NAS is a more expensive and advanced option with some good benefits. Put all your files from both PCs on it and access them all from either at any time, without the other machine needing to be switched on.

Just don’t forget that if you do this you’ll need to either
– use NAS as primary file store and back it up externally or to a large cheap internal HDD in one of the PCs
– use PCs as their own file store and just use the NAS as backup. Not as flexible.

Lots of NAS drives also do loads of other stiff like media server, iTunes server, web and FTP etc.

Dropbox will sync machines on the same LAN over the LAN, so using no Internet BW…..

Theyre on same wifi network, but not able to see each other at all as not setup. The upstair machine is pretty slow, so would like to backup everything to the downstairs pc, either spare internal or external.

BT homehub router.

Do you have a backup plan for the downstairs PC?

Check out ‘Undocumented Features’ on here:
http://en.wikipedia.org/wiki/BT_Home_Hub

Worth a Google to see if you can connect a drive to the USB port and access it from both machines.