I had Win 7, but because of some issues, I dont want it and want XP. I removed the partition C: which had Win7 and recreated it. Tried installation of XP but earlier C: was 100MB and now 86MB but does not allow XP installation as it requires 1100MB. If I go to recovery mode, it ask for Admin password, but dont know default XP admin pwd.
Not to swap them but you are free to rename any drive or Partition except the one with the system on - just make sure you use a higher drive letter - probably at least J.
In your circumstances, unless Mb is a typo, what you're looking at is a small Recovery Partition which does nothing more than point to space on the hard disk where a system image is stored. That has probably now gone so you can delete that little 100 or 86Mb partition then see what others XP offers you.
Because there's a high risk that the entire disk will be formatted, you really need to get your data out of there before going any further. Use a Linux LiveCD to do that - take a look at http://www.pclinuxos.com for a simple system which won't cost you anything. Burn it to CD and run it in RAM, click the Computer icon and follow the trail to the hard disk and your data and save it all out to an external source.