CSC-SY

let your computer boot to the dos system (using dos bootable disk) then execute this command : fdisk /mbr this will return the windows as the first bootable system

sure this will be a shell repair, you have to restore the linux loader (GRUB)
this will be very useful GRUB restore

Hello DarkSide.
Your case is what *NIX users call "Microsoft's arrogance"; Windows boot loader does not recognize other operating systems on other partitions, so, when you've "fixed" your MBR using fdisk (which is a naive approach) you've just deleted GRUB, and installed Windows boot loader (ntldr or whatsoever) on MBR.
However, here is what you can do to restore GRUB so you can dual boot your OSs.
insert FC7 cd/dvd, enter the rescue mode, enter the terminal and type the following:

[1] chroot /mnt/sysimage
This will change to root directory back to normal.

Now, you need to know what's the type of the interface of the drive you've installed your F7 on, type:
[2] cat /etc/mtab
it will list all mounted partitions, the string /dev/???? depending on your system, for example, I have F7 installed on /dev/sda13, all you need to know is the hard drive type and order, i.e. sda.

You're almost done, to restore GRUB back to the MBR, type:
[3] grub-install /dev/?d? (where ?d? is the name of your hard drive as I mentioned earlier).

[4] reboot, and voila! GRUB is restored.

I read from the beginning of your post that you're not comfortable with GRUB configurations, you can modify its behavior by modifying the corresponding file /boot/grub/menu.lst .
Login to F7, open a terminal and type:
gedit /boot/grub/menu.lst (make sure that you have admin privileges)
The file is self explanatory, anyways, find the following line:
default=1
This line indicates the default OS that GRUB will choose to boot when no user interaction is performed during the limited time, change the value to the one that matched the order of the preferred OS (starting from zero).
Now, check the line:
timeout=2
it means that GRUB will wait two seconds before automatically booting the default OS, change the value as you want.
You can make further customization like the name of the OS (for example: instead of "Other OS" type "Windows XP SP2"), you can also change the background, but that is irrelevant.

BTW, obviously that could've solved you problem without messing up MBR and nearly crashing your system by installing Windows boot loader as as_els said, so please as_els be more accurate about suggested solutions next times.

Good luck.

2- cat /etc/mtab <the result was:>
/dev/sda12/ ext3 rw 0 0
proc /proc proc rw 0 0

3- grub-install /dev/sda < the result was :>
/usr/share/grub/i386-redhat /stage1 : Not found

actually, I faced the same problem (lost of windows boot choice) a time ago when I was in 4th year, and I found no way at that time to return the windows boot choice, so the only way I solved is by reinstalling the MBR then the GRUB and this worked

DarkSide if u still have the problem,
as the article said you have to run grub, so search where the grub is located in your system ( /sbin/brub on my CentOS 5 ) , you can try the locate command
#locate grub : this will give u all places grub keyword found in
mostly as i said you'll find it in /sbin/grub so now to run grub
# /sbin/grub

Once started, GRUB will show the command line interface.
grub> find /boot/grub/stage1 if doesn't work try
grub> find grub/stage1
this will output something like
(hda0,0)
now set the GRUB's root device1 to the boot directory,
grub> root (hd0,0)
Once you've set the root device correctly, run the command setup:
grub> setup (hd0)
This command will install GRUB on the MBR in the first drive.
this exactly what solved my problem

anyways, I suggested what I before did for this problem, so really I didn't mean this mess, sorry guys

The contents of mtab indicates that most file systems are NOT mounted, you should've got a relatively long list of currently mounted volumes.
Here's what you can do, first check fstab typing cat /etc/fstab, if the file is not messed up, i.e. contains all file systems you've created during installation.
Now, type fsck -p, this utility checks each file system in fstab and repairs as necessary BTW: it could take hours-
Redo the four steps I mentioned previously, if mtab still gives you the same output, try to mount these file systems manually, which is a long shot since you have to know the exact correspondence between file systems and partitions names, if you could've managed to do that, repeat those steps again.

Good luck,

as_els I tried wot u wrote :
sh-3.2# locate grub <enter>
Command not found

sh-3.2# /sbin/grub <enetr>
probing devices to guess bios drivers. this may take a long time .
Error opening terminal : linux
--------------------------------------

Rammstein here wot happend with me :
sh-3.2# cat /etc/fstab <Enter>

label=/ / ext3 defaults 1 1
label=/boot /boot ext3 defaults 1 2
tmpfs /dev/shm tmpfs defaults 0 0
devpts /dev/pts devpts gid=s,mode=620 0 0
sysfs /sys sysfs defaults 0 0
proc /proc proc defaults 0 0
label=/tmp /tmp ext3 defaults 1 2
label=/var /var ext3 defaults 1 2
label=/home /home ext3 defaults 1 2
label=/usr /usr ext3 defaults 1 2
label=swap-sda13 swap swap defaults 0 0

sh-3.2# fsck -p <Enetr>
fsck 1.39 (29-may-2006)
fsck-ext3 : unable to resolve 'label=/' gh

Just an idea regarding restoring the drive letters, you can change drive letters using Control Panel>Administrative Tools>Computer Management>Storage>Disk Management (in Windows XP Pro).

 

I see that the guys have give you a lot of excellent advice. This feels like the good old days when we used to spend time talking about these things.

 

Just an idea, I think that fedora (apparently) does not automatically add all mountable partitions to fstab when started from the DVD. I didn't know what /mnt/sysimage was supposed to be, but after some googling I found that its the root directory of the linux partition on disk, auto detected at boot time. So grub-install didn't work because it was chrooted to /mnt/sysimage, but /mnt/sysimage was empty.

 

You probably should do like as_els said, start grub (using 'grub --no-curses' to avoid "Error opening terminal : linux", as google informs us), then go on from there.

Actually, when entering rescue mode, it first checks for installed F7 distro then mounts the system automatically under /mnt/sysimage directory.
When you chroot /mnt/sysimage you'll reset root mounting point back to normal i.e. / instead of /mnt/sysimage/, this is the default behavior, abviously, for some reason, there was an error mounting file systems (according to mtab contents), that's why I advised Darkside to run FS check, but, alas! it doesn't work either.

Darkside, if you haven't reinstalled F7 (I hope you didn't decide to get rid of it for good! ), here is my final recipe, try to mount file systems manually, to do this, you need to know the label of each partitions using e2label (which I've heard about today!), for example:
e2label /dev/sda12 (enter)
/var
when you know the label of the partition, mount it:
mount /dev/sda12 /var (enter)
repeat this step as necessary, if nothing went wrong (check mtab), try the four steps I told you about first.

Good luck.

Hello again ..
Here wot i tried 2day ..

i tried 2 upgrade fedora but i had this error :
"Error mounting device sda15 as /tmp: no such file or directory
this most likely means this partition has not been formatted

back to Rammstein's final recipe ..

i mounted the following labels Successfully : sd10(/) - sd12(/usr) - sd11(/home) - sd14(/var)

but i didn't have this success with other labels :

sh-3.2# e2label /dev/sda9 Enter
/boot
sh-3.2# mount /dev/sda9 /boot
mount : mount point /boot doesn't exist

and i tried many sd(x) with e2label but i didn't find any other labels 2 mount ..

then i tried the 4 steps u told me befor ..

sh-3.2# cat /etc/matab Enter
the result was changed and i had abt 18 lines (not only one as in the previous time)

sh-3.2# grub-install /dev/sda Enter
sh :/mnt/sysimage/sbin/grub-install :/bin/sh : bad interpreter : no such file or directory

Thx a lot guys for the ideas and if u have anything 2 try tell me 2day(b4 00:00)
cause it seems i will spend this night reinsatlling fedora7 and if i had any new surprises then Maybe i will "decide to get rid of it for good

You know what they say, Linux is only free if your time has no value. But perhaps you should try a less trouble-making distro, like Kubuntu for instance. I never had any problems with it, but I always deleted Fedora two or three days after installing it....