Is it possible to change default OS at boot?

I don't know what has happened here. In my experience, if you choose a partition to install Windows to, that partition is invariably formatted. And a clean install of Windows 7 shouldn't leave you with Windows old folders. Offhand, it looks like you booted from the DVD and chose the right partition.

Did you see a screen asking you which language you wanted to use, just after you booted from the DVD, before you chose the partition?

But you had a mess originally, with XP hanging around somewhere or other and that's presumably why you have Windows old folders.

You've probably still got a mess. You say some of your software works, but not others, and you have to go to Windows old to poke exe files.

It's up to you. I'd do a clean install, probably using diskpart to wipe the drive after I got my backup drive returned.

Yes, I did get a screen that asked me for language.
I have actually gone through the same steps as shown in this tutorial - Clean Install Windows 7

Its just that at step 8 I clicked the partition to install and clicked next, I didnt click on any of the advanced options there..(as you saw in post 41 pic) Maybe I have to click "Format" in case it doesnt do it automatically ? Possibly if it finds an existing OS hanging around it does not format the drive and just does the windows.old saving and installs win7..

I led you a bit astray by not giving you a complete answer.

When you got to step 8 and saw that partition, you should have deleted it in "drive options advanced". That would create "unallocated space". You would then select that unallocated space as the destination for "where do you want to install Windows". Windows can't install to unallocated space, so it would automatically format it. You'd have a true clean install. Of course, be sure to choose the correct partition to delete. It seems you did have the right partition chosen---you just didn't delete it, you overwrote the existing install.

Try that, with the understanding you will have no windows old and no installed apps.

You may prefer the status quo to that??

Thanks for your input.
This makes a lot of sense..
I will try this again in a day or two. I got some work piled up due to all the problems i created.. So once I am done with those I would probably format and do a "Clean Install" this time.

Poolemahu said:

No I didnt not install any software. What I did was to go to windows.old folder (which I guess is from XP) and open the program files there, browse to the necessary exe and then do a send to desktop shortcut. some of the exe still continues to work normally while others dont but this was the case earlier. software like adobe reader and itunes dont work whereas my work related software all work fine.

The work related software that does work might be Standalone programs, not Installed programs.
That could explain why these programs will run from the windows.old folder, and other programs such as Adobe or Itunes don't run from the windows.old folder.

To test this, copy one of your work related programs from the windows.old folder to the desktop.
Don't just create a shortcut, copy the actual .EXE file.
If the program runs from the desktop it is a standalone.

You can also look in Control Panel / Programs and Features.
If your work related programs are not listed, they are standalone, not installed.

If they are standalone, make sure you copy all these programs to somewhere safe BEFORE getting rid of the windows.old folder.
"Standalone / Portable" programs can run from anywhere...no installation needed.

You are right. Only the standalone ones work the others wont.
I try to delete the new windows.old.000 folder but it doesnt allow me to do so. It says it needs permission from "TrustedInstaller" to remove the files. Now how can i delete them?

I believe you need to make some changes with permission and ownership for the windows.old.000, where you take ownership of this folder.
I'll see if I can find a tutorial explaining this.

See if this tutorial by Brink helps.
How to Take Ownership of a Item in Vista and Windows 7

Thanks David, I will go through it and let you know.

Use Disk Cleanup to get rid of windows.old.

Then post back screenshots of each drive's Explorer window showing all files on that drive. We can spot any old OS and advise you the best way to move the needed data off that partition so you can delete and Extend C or the remaining Data partition to distribute the space. I'd do this down to two total partitions. PW Extend makes it easy to get both the exact size you want. How to extend partition easily with partition magic ? Partition Wizard video help.

The XP Setup would only appear if you had been trying to install XP and not just its SP3. Those files may be still there to delete along with the other XP which worked. If we delete their partitions they should go away, can be deleted in msconfig>Boot tab, or the hard drive needs wiping with Clean command to clear errant boot code.