Solved the problem using Partition Wizard, thanks to the whs, check link: (Solved) - Dual OS - Swapping Primary with Logical and vice versa. « How-To Geek Forums
But need to fix the drive letter which is D: and i cannot change it to C: as not allowed. Further 'boot.ini' missing message was displayed during system booting, now having fixed it by copying it to D: root system boots normally. Now 'boot.ini' tab is missing in 'msconfig'. So run 'regedit' then checked path HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Shared Tools\MSConfig\state. In right pane deleted all *.ini including boot.ini. Booted the system and again run msconfig all tabs viz. General, System.ini, Win.ini, Services, Startup & Tools appeared but Boot.ini. How to solve this and drive letter problem.