I am looking for ways to restore my system to a previous state easily.
I am using Windows Vista and ubuntu.
Try looking on this Lifehacker article: Five Best Free System Restore Tools. I think Macrium Reflect Free is probably the best of the bunch.
If you're looking for a Free/Open-Source Software tool, I can recommend http://www.clonezilla.org/
I have been using PING very successfully.
GNU Parted has a broad set of features and is similar to Ghost.
It can detect, read, create, grow, shrink, move, copy, check and label partitions.
It comes with almost every linux boot CD and the website offers a GParted Live system which can boot from CD, USB, HD or via PXE. You can even order ready-made CDs.
It supports a large list of filesystems. Especially NTFS is very well supported.
When you copy a partition the image file can be anywhere the underlying linux system can read it. Additionally there is a parted server application. If you have to deal with many image files you can set up a parted server an fetch the images from there.
For addtional information see the GParted FAQ.
I know this question is somewhat older, but I thought I offer another solution.
I'd like to encourage you to consider partimage. I've always loved partimage. It's incredibly capable at making partition backups for quite a few different partition types. It now supports Ext2, Ext3, FAT-16, FAT-32, HFS, JFS, NTFS, Reiserfs3, Reiserfs4, UFS and XFS.
The trouble has always been partimage's command line is a bit dense. Not to mention, if you wanted to backup to a network destination, Partimage requires you mount the remote share before you fire up the GUI.
We decided to create a GUI wrapper around Partimage to handle these details. We called our tool 'Kleo' (named after the Greek Muse of History & Archives). It's a simple wizard style interface that walks a user through the process of creating a complete partition backup. It handles finding, suggesting & even mounting network targets, and it handles the details of invoking partimage correctly.
The resulting backup files are standard partimage files, so recovery could be done either using Kleo in Recovery mode, or just firing up a copy of partimage from any Linux distro.
We decided to bundle it with an Ubuntu 9.10 remix we created that we call the Carroll-Net Server Recovery Kit. We dropped a bunch of great apps on it we always like to have at hand when dealing with server backup & recovery tasks; GParted, NTpasswd, Memtest86, Install-mbr, Gpart, Dd_rescue and many more.
Both the Carroll-Net Server Recovery Kit & Kleo are completely free for any use. The Server Recovery Kit is GPLv2 and Kleo is released as Freeware.
You can read more details and down a copy from http://www.kleobackup.net.
(Ignoring the ubuntu:)
What about Disk2VHD from http://technet.microsoft.com/en-us/sysinternals/ee656415.aspx ?
That looks good, uses volume snapshot, works on xp, images can be mounted with Virtual PC (up to 127gb) or Win7.