Windows 7: XP cannot access other drive with Windows 7 dual boot

I've got a bit of a perplexing problem here that I hope somebody can provide some insight on. Set up the dual boot with your (very awesome) tutorial and everything works perfectly there. Windows 7 was installed first to the C: drive, XP is on an E: partition of the same drive. The D: drive is a second physical drive that is just used for file storage. If it matters, both physical drives are paired drives in Raid1.



The problem comes when I've loaded into Windows XP, I can't access the D:\ storage drive. It reads as size 0, and can't be formatted or read.

Under Windows 7, everything works. I can access the storage drive fine and have no problems using it.

I originally thought it was a permissions thing because the D:\ drive was formatted in Windows 7, but in XP I can read from the Windows 7 C:\ drive just fine.

I am at a loss, can anybody offer any suggestions as to why the drive would read fine under 7 but not when in XP?

Hi NP and welcome

I assume the drive is NTFS. what are the permssions like. since the HDhas been in two OS maybe the inherited rights are different.

Not much help sorry

Ken J+

I spent the better part of the day banging my head against the wall on this, then I came here and made the post and went to lunch. I think the bit of time off away from the problem helped, because I came back with a solution.

I completely deleted the partition on that storage drive from in Windows 7, then loaded up XP and formatted it there. After doing that both Windows 7 and WinXP were able to access the drive fine.

Not sure what the actual issue was as there was nothing special about the original format (default NTFS), but at least now there is a fix on record for anybody else unlucky enough to have the same random issue.

Hello NinjaPirate,

I've run into a similiar problem with Vista/XP.

This may be why: http://www.multibooters.co.uk/partitions.html

Windows 7 uses Vista rules as outlined in the above article when creating partitions which XP can't follow.

Edit: Adding a warning for anyone that uses Windows 7 or Vista to image/restore the XP OS partition. Have to change Windows 7's/Vista's Registry to follow XP's partitioning rules, otherwise - deep doo doo. That's how I became aware of this issue.

So the issue re-appeared. It works fine when I format it in XP, and stays fine when flipping between the OS's, but the instant you copy files to the drive in Windows 7, the drive becomes unreadable in XP (but still works in Windows 7).

Tried the registry edits per the last post to force 7 to use XP's method for partitioning drives, but it didn't help. At this point I've got nothing. Ideas?


Edit: Partition management programs will properly identify the partition information when run from XP, but XP itself will not.

I noticed in your previous post, you write that you used Windows 7 to create the partition and had XP format the partition.

If you have not done so, recreate the partition using XP - not Windows7.

Good luck.

I had a similar issue using a third hard drive mutually between Xp Pro SP3 and Windows 7 Ultimate, both OS's 64-bit. The first drive had only Windows XP, the second drive had only Windows 7. Both OS's used the third drive successfully, but the files and folders were listed separately.
In explorer I would find all the folders and files created by Windows XP, then all the folders and files created by Windows 7.

It may not seem like a problem, but before I realized what was happening, I thought I had a serious issue. I couldn't find some files and folders I had just created.

I didn't find the answer but I believe it's a similar issue. So I'm hoping to learn the answer.

Tried that, result is the same.

This is an old thread, but I'm having a very similar problem with an external drive. No solution or explanation?

I started another thread here:

Windows XP Pro won't recognize external drive formatted in Windows 7

After further investigation, I noticed that the drive appeared in the disk management utility on Windows XP as a "GPT protective partition", thus Win XP could not access it.

This came about via my own lack of knowledge when I initialized the new disk in Windows 7 and selected "GUID partition table (GPT) partition style". I should have selected the master boot record (MBR) method.


I couldn't figure out how to revert the disk. A quick web search for "GPT protective partition" led me to this page:


How to delete GPT Protective Partition - Paul Gu|blog


In Win XP, I followed the command prompt instructions given on that page, and re-initialized, formatted NTFS, etc. Now the drive works fine in both OS

Fortunately I had very little data to lose, but it was an exercise in wasted time due to my own ignorance.


Thanks to AddRam for some good advice as well (Partition Wizard Bootable CD) - Had I heard it before I reformatted it may have saved me some time and effort