How do I partition an existing Windows 7 OS?

Your plan is fine, and you can indeed use Partition Wizard bootable CD if in the second shrink operation Disk Mgmt will not shrink C: enough. Always back up your files any time you use a 3rd party DIsk Manager.

However you might also need to use the best tool which will move System files if they are blocking shrinkage: Perfect Disk 11's trial version Offline/Boot time defragger for System files.

After downloading PD, set Defrag drop-down menu to Consolidate Files. When this completes, attempt shrinking again. If that is not enough, then rightclick C: drive and do Offline or Boot time defrag selecting "System" files.

whs said:

1. Leave the 100MB partition alone. That is your boot partition. It should be called "active". Just don't touch it.
2.All you can shrink with Disk Management will be the 430GBs. Later it will not let you shrink any more - that's why I suggested Partition Wizard. The reason is the MFT that Disk Management will not move, but PW will. Another problem would be that the freespace you want to add to a partition has to be to the right of that partition (with Disk Management). No way to extend a partition to the left - except with Partition Wizard.

I have a question. As of right now, I'm dual booting XP and Seven. I have one disk, two partitions. C: has XP which was installed first, E: has Win 7. Before installing Win 7, I shrunk C: of course to create E: to install Win 7. At the time I really didn't think I would use Win 7 all that much and used little more than the minimum space for the installation of Win 7. As it turns out, Win 7 appears to be great and now I regret not having more space on E: for it. Here comes the question, can I shrink C: and add the space to E: Win 7? I've always assumed I couldn't but honestly don't know for sure.

Thanks, everyone, for your response and help to my post.

You all raised very good points and concerns. I have read all the associated information and links and now feel comfortable to partition my disk the way I want it to be. I've purchased Acronis for backup and got Partition Wizard for Home Edition to help me better move and create partitions.

Now to work.

Greg S, do you want to delete XP before you resize Win7 into its space?

If so you'll also need to use free Partition Wizard bootable CD: mark Win7 Active using Partition Wizard, do the delete/resize, then apply all steps.

Now boot into Win7 DVD Repair console or Repair CD, click through to Recovery tools list to run Startup Repair up to 3 separate times with reboots until Win7 will start.

gregrocker said:

Greg S, do you want to delete XP before you resize Win7 into its space?

Negative, I'm just looking(if possible) to add space from C: partition to E: partition which has Win 7. Before installing Win 7 I had only the one disk/partition which has XP. I used Gparted to shrink it by 17+ gigs which was used for E: to install Win 7. I'm fully backed up going back as far as the day before installing Win 7(10/23/09) to the most recent about 3 weeks ago.