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It seems like using Virtual PC 2007, if an "Undo" disk option is selected when setting up this Virtual PC, you can play with the Virtual PC for a few hours, install all sorts of software, toolbar, etc, etc. And at the end, when you shut down the Virtual machine, just don't commit the change to the hard drive, and NOTHING ever happened to hard drive? Is it that good?

If it is that good, I wonder how it compares to creating a restore point first, and then after a few hours, restore the PC to the state before... Of course, I think the installation can create a bunch of files (and the user can create a bunch of files) and the "restore" won't restore those back...

But the "undo" disk, it will be as if nothing ever happened to the hard drive?

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up vote 3 down vote accepted

You are correct. The undo disk can take up a lot a space though. At our shop we decided to skip the undo disk and instead keep a copy of the hard drive file. When we want a fresh machine we copy the virtual hard drive file over the existing vhd file and we're good to go.

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so do you update this "fresh machine" once in a while? like if there are a few security updates, will you use a fresh machine, do the updates, shut down the machine, and now use this as the "new machine"? – 太極者無極而生 Nov 4 '09 at 13:38
If by "once in a while" you mean maybe once a year if someone thinks of it, yes ;-) – Beaner Nov 4 '09 at 16:34

That's exactly how we use VirtualPCs for application testing here. You mess around on the PC, install stuff, break stuff, and then close it down without saving the Undo Disk changes and it's as if you never touched it, anything stored on the hard disk and not saved to the network is gone as if it never existed.

Restore Points are different as they only watch for changes to certain key components and installs. If you write documents to your My Docs, or copy a few extra files to odd places (or change or delete them) they don't get reset. Undo disks reset the slate on the whole disk as if your previous session never happened, system restore poimts only save and restore the important parts of your disk back.

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