Installed Win 7 in dual boot. Now XP doesn't see one of my hard drives

Answered  I got it going thanks to everyone on here!!

Probably first of all you need a Professional version of an OS to allow two OSs on the computer. And 25Gb for Windows 7 is not really going to work since it stores an additional copy of the OS usually with the OS in case something goes wrong with it (well on my computer it does) so you need probably more like 70Gb to be safe, maybe less. I don't have much on my C:\ partition which is the primary partition and the active partition that starts up the computer and loads the OS in the first place.
 
The formatting in XP may be different than Windows 7 which has to be NTFS (new technology file system). Well I would have to check my old XP computer to know what I have in XP anymore, but with XP I could also have Fat32 formatting or even the original Fat16 formatting for old ms-dos games which I do have on my XP computer. Fat32 is 32 bit formatting (like Windows 98) and Fat16 is ms-dos or 16 bit formatting like Windows 95 or ms-dos.
 
Now it may be different for Windows 7 if you have a DVD with the OS on it, but usually on newer computer they do not include a DVD anymore with the OS - they have another copy of the OS on the harddisk like mentioned above if anything goes wrong with the OS and recover DVDs you have to make on your own, or even DVDs with the OS on it on your own. You do not get your own DVDs with the OS on it  anymore usually and the manufacturer of the computer would have its own program on the computer for all of that - or you can make a backup in Windows 7 or the harddisk partition (for the OS) or buy a program that does that kind of backup and all of that kind of stuff to insure that you do not lose your OS. You usually should have back up on another harddrive because if the original harddisk drive fails, then when you put in a new harddrive, you can re-install the OS from the backup or from the DVDs you made. That is just the way they do it now, and even if not, then the manufacturer may have a cloud kept version of the OS you can download from them again, if you have your computer registered and all of that stuff.
 
Way back when Windows 2K was out, the only way back then to have two OSs on a computer is one of the versions had to be the Professional Edition of the OS so two OSs could be installed. I have not done that since so I do not really know how that has changed or if it has changed.
 
You should really do some searching on the Internet and put in things you do not know and read about it, even perhaps at the manufacturer's website perhaps, but there is a lot of info out there, just make sure to find the correct info on computers - and on forums for the OS and whatever.
 
Also like mentioned up above for the formatting, I think that Windows 7 can read a Fat32 partition, but you will need third-party software to format any partition that way, because the only formatting Windows 7 (or Vista maybe I do not know) is NTFS type formatting. XP may be that way also, but other formats could be done in XP but not in Windows 7 without third-party software.
 
http://www.partitionwizard.com/free-partition-manager.html
or perhaps Partition Magic (which I use to use but then - you would have to search for that software if made anymore).
Two different programs.
 
And no doubt that is why XP can not see one of your disk because you have changed your computer and now the OS is lost as to what you are doing probably. But do a search for any info you need and really find out.
I have not tried everything so I am just going by the past and what I did on my old, old computer not used anymore with Windows 2K and having two OSs on a computer.
 
If XP was the professional version of the OS then what you did should work and you should have a choice as to which OS you boot up the computer with, but if it was not, then Windows 7 should have taken over and that would be the only OS you can boot up the computer with. As to why it would not see the harddisk then if you had the professional version of the OS then the formatting of the harddrive probably has something to do with it then.
( and the type of formatting on the harddisk).
??
 
 
 

The os isn't lost.  it boots up to xp fine!
 

HighAndDry
The os isn't lost.  it boots up to xp fine!

If you could answer #2 that will help all of us and bring some clarity about what the issue actually is. Just trying to keep things simple (there seems to be a lot of speculation). Thanks.

I tried to do a screen dump but it didn't work.  In disk management the drive shows up as dynamic and labelled foreign. with the yellow caution sign over it. When I try import it the operation fails
 

windows 7 sees it fine in disk management  healthy disc   Its xp that shows it as foreign. dynamic. with the yellow symnbol over it.  when I right click the options are import foreign disk and convert to basic disk.  the other options are greyed out other than properties and help

Ok I can probably move the data onto the new 1 tb drive in win 7.  that is what I will try to do.  Now.  when I format it again will it be a dynamic or basic.  I mean what is the difference?  I think it has to be basic ton install an OS

HighAndDry
...I think it has to be basic ton install an OS

You're confusing me now.  I thought you said that the problem drive was the one you use for storing your projects.

CakeAlexS
> windows 7 sees it fine in disk management  healthy disc  
 
I asked you:
"could you please confirm how your problem partition is formatted (anything other than NTFS?)"
And also for a screenshot (I provided instructions in my last post).
 
We really need to know how it is formatted in Windows 7. Please ignore what XP says for now as it could be reporting anything. Until we actually know the detail I strongly recommend holding off any action.
 
I am just trying to help you avoid doing anything unnecessary or dangerous. Any formatting to be done should be done in Windows 7 anyway and not XP, but we really need to know what your unidentified partition in XP actually is (Windows 7 is going to tell us that).

Thanks.

Yes you did.  a screen shot from windows 7 wouldn't help because that OS sees it fine.  
  Anyway, I backed up the data and formatted the drive (in Win 7) just quick format  Now disk management sees the drive in XP.  so the good news is that I have the data..  I am now formatting it NTFS in Win XP and it is already showing up in my computer with only 2% formatting
Thanks for the help   Hopefully that will take care of it.  

CakeAlexS
> a screen shot from windows 7 wouldn't help because that OS sees it fine.  
 
With respect a screenshot would have helped us find out what the issue is, that is why I requested it. You were the one asking for help after all and I try not to ask silly questions. We could have identified what your actual partitions was formatted as, and we never actually found that what that partition was in the end (i.e. NTFS, WinFS, Win32). Also we could have given you the wrong advise if had misunderstood your first post (and it appears some people had). Telling people to format a drive is something I would never do unless I was absolutely certain. Regardless you never supplied us the information that we asked for.
 
I did say earlier it is better to format it in Windows 7 rather than XP- anyway hope it works (it should be if it's NTFS although I would have still used Win7). There could have been other options available which may have been better but it looks like you didn't really need our help anyway (and I could have helped somebody else instead who need it, it is frustrating!).
 
Next time please try the windows forums, and good luck!

I'm sorry I didn't mean to appear disrespectful. I am grateful for the help.  I tried to do a screen dump in xp (which is where the problem was) and was unsuccessful. I understood your directions to be pertinent to windows 7 (snipit) Windows 7 saw the drive fine so that wouldn't have helped. (And I am a newbie at posting photos to forums.  I need to get up to speed on that)   I tried to give as much info as I could regarding disk management in xp. yes the screen shot would have removed any doubt I guess.  And I remembered you saying formatting in win 7 would be better after I started the XP format.  but thanks again!!And sorry again if I appeared disrespectful or ungrateful!

HighAndDry

CakeAlexS
> a screen shot from windows 7 wouldn't help because that OS sees it fine.  
 
With respect a screenshot would have helped us find out what the issue is, that is why I requested it...

...Windows 7 saw the drive fine so that wouldn't have helped...

A screenshot of Disk Management would show us useful info, including an overview of your drive system.  It's not just about whether one particular drive is visible.

Anyway I'm glad you got it sorted.

KPerry
Backup the data on the project disk (or copy to the new 1TB drive), delete partitions in XP (or Windows 7 if you have to) then recreate a basic NTFS partition in XP.

I believe he's already beyond that.

KPerry
Reading on 'phone...hard to get to the end :-)

I can't work like that.  I like a big screen (or maybe two).

We still don't know what the OP issue was (Windows 7 would have reported it not XP).
My hunch was he was using a partition format not compatible with XP. Anyway point is moot now, he's resolved it appears (please mark post as answered).