Backup software: have several PCs backup to Win7 PC

I have a raid 5 array attached to a windows vista PC. (The PC is on all the time so seemed a good idea at the time).

There are many desktops and laptops in the house that need better backup strategies.

Is there good software that would make image and incremental backups ?

I tried a copy of Acronis True Image that is the free download from Western Digital. It ran for 2 days making the backup image (5 to 10 MB/sec over network). Problem was twofold. Acronis got roughly an error every hour and put up a message saying "click to retry or skip" then defaulting to skip when I didn't reply in 10 mins. Acronis also aborted the backup failed 80% of the way thru. I have a single licensed full copy of ancronis 2010 but didn't see any point in trying that since I'd be buying a different version for the other PCs.

Any other software I should try? I'm thinking of something Client/Server where I could run the server component on the PC with the 8TB raid 5 array and the clients on the PCs being backed up. Open source would be nice as long as client supported windows.

(Aside, enterprise software like TSM will do this, but the price is WAY outside the $50-$100 I'll pay for backup software).

Thanks for any suggestions.
 
Solution
How about mapping a network drive on each machine pointed to a shared folder on the Raid array. Copy any data over to this share, and then always use this share for any data. Now all you have to do is backup the raid 5 array from the vista machine to an external drive - preferably you will have 2 external backup drives. One at the house, and another at the office, or some off-site location.
How about mapping a network drive on each machine pointed to a shared folder on the Raid array. Copy any data over to this share, and then always use this share for any data. Now all you have to do is backup the raid 5 array from the vista machine to an external drive - preferably you will have 2 external backup drives. One at the house, and another at the office, or some off-site location.
 
Solution
This will work, and I am using it this way now so this is a solid suggestion.

What I'm missing: (1) If the hard drive fails on one of my PCs I do not have a bootable backup image. (2) User intervention is required to backup the right information and I do not have (or want) first class access to the kids PCs - but I do want to cover them for a drive failure.