Windows cannot install required files. Error code: 0x80070017

Something that could go wrong while installing Windows 7. The backup, partitioning and other pre-requisites complete just fine. But when the installation begins to extract files and data from the DVD, you get a big error which says:

Windows cannot install required files. The file may be corrupt or missing. Make sure all files required for installation are available, and restart the installation. Error code: 0x80070017

More often than not, the simple reason behind this error is just that the DVD burning caused some little problem somewhere and corrupted a file.

There’s no quick solution, just re-burn the Windows 7 RC on a new DVD with as low a speed as you can stand. 2x or 4x should be OK. Some people are also saying that the DVD- format works more times than DVD+, but I think just lowering the burn speed should do the trick.

Startup disk cannot be partitioned or restored to a single partition

Software sometimes behaves stupidly and in the most unlikely of places. Here is one such – when you start the Boot Camp Assistant in Mac OS X Leopard to install Windows, in stead of proceeding from the first – informative - screen, it throws an error:

The startup disk cannot be partitioned or restored to a single partition. The startup disk must be formatted as a single Mac OS Extended (Journaled) volume or already partitioned by Boot Camp Assistant for installing Windows.

This, when you have a brand new Mac with a single clean partition.

The problem is that the Boot Camp Assistant, for some reason, is thinking that you have more than one partition of your startup disk - the disk from which Mac OS is starting up, and Windows is intended to. More than one OS X partitions, that is.

The solution is quite simple and quick really (except for the backup step):

1. First of all, backup all of your existing data. A Time Machine backup is advisable. You should do this any time you want to play with the partitions on your hard drives – even with the correct tools at hand.
   
2. Add a new partition using the Disk Utility as perfectly described here. Close the Disk Utility.
3. Now, remove this newly created partition, again, as given here.
4. After this, the graphic of the hard disk will again show up as one full partition.

That’s it, really. Boot Camp Assistant won’t show the same error again.

Although the problem is less baffling when you already have multiple partitions created, the solution is still to remove all partitions other than the startup one to enable Boot Camp to proceed without errors.

Just a word of caution. Boot Camp does not understand a partition created before its invocation, even if you created it expressly for installing Windows. So it’s best to let it do it on its own.