Save space when using two drives or dual-booting

Scott dunn By Scott Dunn

You may be able to free up some valuable space if you’re using two disk partitions, using two physical drives, or dual-booting between XP and Vista on the same machine.

I’ll show you several steps you can take to eliminate duplicate files and get more out of your disks.

Decide on your multiple-partition strategy

Years ago, it was common for users seeking more reliability to divide a hard drive into two or more partitions: portions of a disk, each with a different drive letter. Back then, recovering data from drive d: was easier than from drive c: if the primary partition (containing Windows) became corrupted.

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That configuration is rare today, because backup programs and disaster-recovery services have improved. But there are still three situations in which you might find yourself handling two or more partitions or physical disks:

1. Multiple physical drives (internal or external). When space grew scarce on your c: drive, perhaps you added an additional drive d: to get more room;

2. Separate code and data partitions. You created separate c: and d: partitions on a single hard drive, installing Windows on the first partition, but c: is now running out of space and you don’t wish to run partition-management software to change the size of the partitions;

3. Dual-booting. You installed XP and Vista on the same machine in a dual-boot configuration, which requires that the two operating systems be installed on separate partitions.

I explained how to dual-boot between Windows XP and Vista in the Feb. 14 newsletter. In a Feb. 21 article, it was explained that XP in a dual-boot system steps on some Vista data. In a nutshell, booting into XP (a) deletes any system restore points created by Vista, including the “shadow copies” that are created by Vista Business, Enterprise, and Ultimate, and (b) deletes all but the most recent Complete PC Backup, if that application was used to back up Vista.

Microsoft has acknowledged the problem and has published some workaround techniques, which were described in our Feb. 21 article. One workaround is to edit the Registry so XP cannot see the Vista partition, preventing XP from affecting it. The steps are explained in Microsoft Knowledge Base article 926185.

Having a good backup routine eliminates the need for Vista’s system restore points, shadow copies, and proprietary backup program. If you’re confident of your backup procedure, you don’t need to hide the Vista partition from XP in a dual-boot configuration. If not, the workarounds recommended by Microsoft are currently the only fixes that the company offers.

Reduce duplication with space-saving tips

Once you’ve determined which kind of multiple-partition system you have and whether to protect Vista from XP in a dual-boot configuration, you can start moving things around to save disk space. The following sections describe easy ways to eliminate overlaps and make more room for your own stuff.

Share virtual memory

If you’re booting into both XP and Vista, each operating system will use a portion of your hard disk as virtual memory. You can save space by having both OSes use the same pagefile: a file into which Windows swaps code and data.

If you use the Microsoft workaround mentioned above, Vista will be able to see the XP drive but not vice-versa. Therefore, it makes sense to use the paging file that’s already on the XP partition. If you have a separate physical hard drive, Microsoft says in KB article 314482 that you’ll get better performance if you put your virtual memory file on a different drive than Windows. Here are the steps to take:

Step 1. Press WindowsKey+R (Win+R) to open the Run dialog box.

Step 2. Vista only: Type SystemPropertiesPerformance and press Enter.

Step 3. XP only: Type control sysdm.cpl and press Enter. Click the Advanced tab and, in the Performance section, click Settings.

Step 4. In both Vista and XP, click the Advanced tab in the Performance Options dialog box. In the Virtual Memory section, click Change.

Step 5. Vista only: In the Virtual Memory dialog box, uncheck Automatically manage paging file size for all drives.

Step 6. In both Vista and XP, select the c: drive in the Virtual Memory dialog box (or whatever drive letter the currently running version of Windows lives on) and select System managed size. Click Set. The operating system needs to keep a paging file on the Windows drive to store a memory dump with debugging info when certain errors occur.

Step 7. Still in the Virtual Memory dialog box, select the drive that the two versions of Windows will use for the shared paging file. Enter amounts for the initial and maximum sizes. If you have enough disk space, set both the initial and maximum values to the same figure, which can improve Windows’ pagefile access speed. (See KB 314482 for Microsoft’s recommendations on optimizing the size and performance of paging files.) Click Set. Click OK until all dialog boxes are closed.

Step 8. Boot into the other version of Windows and repeat Steps 1 through 5 to ensure you’ve specified the same settings and drives for both OS versions.

Share IE cache files

Since you may browse many of the same Web sites in both versions of Windows, it makes sense for Internet Explorer to store its temporary files in the same location.

Step 1. Optional: If you want to create an entirely new folder for temporary IE files, create the folder now.

Step 2. Most people will probably use the existing folder that IE created under XP. If so, make sure that hidden files and folders are visible in both versions of Windows. To do this, Press Win+R to open the Run dialog box. Type control folders and press Enter. Click the View tab. Select Show hidden files and folders. Uncheck Hide protected operating system files (Recommended) and click Yes when scolded for unchecking the box. Click OK.

Step 3. Press Win+R to open the Run dialog box. Type control inetcpl.cpl and press Enter. Under Temporary Internet Files (IE 6) or Browsing history (IE 7), click Settings. If you are running XP and plan to continue using the current location for these files, make a note of the path next to Current location in the dialog box. Otherwise, click Move folder, select the folder that will hold your cache files, and click OK twice. Follow the prompts to let Windows log off and move the files.

Step 4. Boot into the other version of Windows and repeat Steps 2 and 3 to make both versions of the OS use the same folder.

Reduce application duplication

Both Vista and XP have a folder under which applications are installed by default. You’ll probably want to leave these folders in place for applications that you will only use in one version of Windows or the other.

On the other hand, many applications work well in both versions of Windows, including Microsoft Office 2007 and the Adobe Creative Suite. In those cases, you’ll save disk space by installing these applications into the same folder. You’ll have to run the installer twice to make sure all the necessary Registry entries are present in both XP and Vista.

You’ll still have some duplication of files that each application stores in the user’s profile. But at least the bulk of the application files themselves will reside in one place, saving disk space.

Again, if you use the workaround recommended by Microsoft to protect Vista’s system-restore data from XP, you’ll want to install most of your applications on the XP drive letter or partition.

Step 1. Run your application installer as you normally would, but use its “custom” option (or equivalent) to specify the folder where the application will be installed. Specify a subfolder underneath the Program Files folder on the XP drive.

Step 2. Boot into the other version of Windows and repeat Step 1.

Unify document organization in special cases

As I discussed earlier, you may not care about system restore for Vista, because you already use another backup product or a versioning tool like File Hamster. In that case, you can make Vista and XP both use the same Documents or My Documents folders on a drive that both can access.

Step 1. Create a folder for your documents on a drive that both Vista and XP can access, such as the c: or d: drive. Note: if you use a folder on the XP drive, booting into XP will delete any system-restore or shadow-copy data created on this drive by Vista, as described earlier.

Step 2. In Explorer, right-click the My Documents folder (in XP) or the Documents folder (in Vista) and choose Properties. In the Target tab (in XP) or the Shortcut tab (in Vista), enter the path to the desired folder and click OK. Respond to any on-screen prompts to decide whether to move existing files or just target the new folder.

Step 3. Boot into the other version of Windows and repeat Step 2.

For more dual-booting tips, such as ways to store chat logs, buddy lists, and Firefox profiles in a single location, you may find a Life Hacker article to be useful. This article discusses dual-booting between Windows and Linux, but you should be able to make the necessary translations to XP and Vista, if need be.

UPDATE 2008-03-20: There’s an additional way to get a system with XP and some people will prefer it. Microsoft channel policy maintains another pipeline for obtaining systems bundled with XP, at least through January, 2009. Redmond allows organizations to apply for a “system builder” classification, a category that covers operations that range in size from substantial box builders to two-gearheads-in-a-garage shops. System builders can purchase OEM versions of Windows XP all through 2008 for bundling with PCs they sell. See our Mar. 20, 2008, article.

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Scott Dunn is associate editor of the Windows Secrets Newsletter. He has been a contributing editor of PC World since 1992 and currently writes for the Here’s How section of that magazine.
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