Windows 7: Unable to launch old OS after installing a new one(dualboot)

Hi,
I had 2 windows 7 operating systems installed on my PC.One of them was getting slow so I decided install a new one over it.I installed the new OS over the old one's partition.Everything was completed successfully.After some time, I decided to switch back to my other(old)OS.But instead of loading windows,it straightaway went to startup repair!One of my other partitions is protected with bitlocker.The startup repair asked for that long recovery key!I entered it and it continued to repair the OS.I checked the log file and it describes the problem as "Bootmanager failed to find OS loader" and the follwing repair was done: "Boot configuration data repair".I clicked the finish button and the rebooted the OS.But the same process occurs again and again.Please help me out.

Please post back a screenshot of your maximized Disk Management drive map with listings showing all columns, using the Snipping Tool on Start Menu.

Tell us what is on each partition and what you'd like to do.

Thanks gregrocker.Here,C is the partition to which I have re-installed Windows 7.And I have Windows 7 installed on partition G as well.Partitions D,E,F are mainly used for storage and partition D is encrypted using Bitlocker.

Now the problem is that,ever since I reinstalled Windows 7 on this (C here) partition,I'm not able to boot to the other OS.As soon as I select the second OS,the startup repair starts and I'm asked for the bitlocker recovery key of the D partition.After entering the key,it performs some repair routines and says that everything is finished.I checked the log file then,and it describes the problem as "Bootmanager failed to find OS loader" and it also describes the repair process as "Boot configuration data repair".I then closed the log,clicked finish.System restarts but the same process of startup repair happens again and again when I select this particular OS.The latest OS I installed did something to the bootloader?

Strange that G has no page file or crash dump enabled. It should have a Page file if it is a working OS.

You may have an insurmountable repair job with bitlocker in the way. I would try Repairs from the DVD or System Repair Disk.

When you boot into Repair it should show both installations to Repair so that you can highlight the one you want repaired and run Startup Repair repeatedly.

If it doesn't show G to Repair then it is not even being read and would need marking Active to run Startup Repair - Run 3 Separate Times to try to move the System boot files to G from SysReserved for the purpose of starting it. You could then add C using EasyBCD to have a jerry-rigged Dual Boot from G. I would back up an image of both OS's and Sys Reserved before trying this, as well as separate full data backup.

Better to copy your data off of G from C and clean reinstall to G if you really need a second Windows 7 on the HD. Remember you need a separate Product Key to legally run both.

Remember also to always boot the installer to correctly install Windows 7 so that it conveniently sees itself as C when booted.

Thanks Greg.I used the System Repair Disk.I changed the name of the 2nd OS to Windows 7 (old) for convenience.Both the OSs were shown(before it bitlocker recovery key was asked for and I canceled it) and I executed the startup repair once.It was completed very quickly but the problem is still there.I also executed the bootrec /fixboot command in command prompt.I want to get into that Windows 7(old).I have certain things to do in it before I can think of a format or reinstall.

So,what should I do now?Run the startup repair 2 more times?
Would you please explain that EasyBCD part a little more?It's a proprietary software right?

If you need files from G then browse there from C as I suggested, copy them to C or externally.

If you choose the correct OS to repair and it will not repair, then run Startup Repair a few more times. But if it still fails, your only repair option may be to move the System boot files from System Reserved to G by marking it Active then running the 3 Repairs to see if it will start.

If G starts and now holds the System Active flags, in order to start C you'll need to add it from G using EasyBCD: EasyBCD 2.0.2 - NeoSmart Technologies

None of this is assured and I would myself copy data over from G to C (or externally) and clean reinstall to G if you really need two Windows 7's.

If you cannot see the data on G from C, use this method to copy over data to C or out to external HD: Copy & Paste - in Windows Recovery Console

Oops I made a mistake in my last post.The Startup Repair program didn't execute successfully.It is asking for a restart after removing any devices viz. a camera or a portable music player.I have the System Repair program loaded from a USB drive.

I have no problem even if I lose the current OS.It has nothing in it.What I need is the other OS.Not just data,I have many settings etc in it for which I will need to run a few programs that I have installed and I have a bunch of organized firefox bookmarks to backup
So I have to make G an active partition?I can see the data on G but how can I access the system reserved 100MB partition?

I would not have confidence in a bootable USB running WinRe unless it has worked before.

Better to try using Windows 7 DVD Repair console or System Repair Disk, or if you dont' have an OD write the Windows 7 ISO to flash stick using Universal USB Installer with Windows 7 in dropdown.

Then try the Repairs again a few times to see if you get any traction, report back what it finds.

Copy out any data on G and C first and save a Windows 7 backup image of both if you decide to mark G Active, then run Startup Repair 3 times to try to boot it. Partition - Mark as Active (Method Two).

But there are no guarantees because we do not see many Repairs being done against BitLocker.

I have an optical drive but I'm still searching for an empty disk .I think WinRE has worked before from USB drive.I formatted,made it primary and active using diskpart.Anyways I will give it a try from the optical drive.What's the meaning of error code 0x0?The startup repair log file(in WinRE) showed a bunch of these and at the end showed that the OS managed to boot successfully!I will post the exact thing here in a minute.

Should I turn off Bitlocker on Drive D?

If the stick has run Repairs successfully in the past, then fine. Is it the full installer or just Repair image?

You can try turning off Bitlocker.

Good quality CDs and DVD's are 5 for $2 on the rack at Walgreens, near the camera dept.