After using re-installation DVD I have a small recovery partition partition C: and the main operating
system in partition D. I had expected the OS in Drive c: and. not particularly interested in keeping the recovery partition.
Do I need a third party software to do this?
If you don't care about the recovery partition, just blast it away. Then rename D:\ to C:\ . Then use a partition manager to reclaim that unused space.
Not 100% sure this will do the trick. But at least it wont be worse.
Open Administrative Tools in Control Panel, then open Computer Management, and in the window that opens click on Disk Management.
Find and right-click on the RECOVERY partition, than click on "Change Drive Letters and Paths...". In the window select the letter and click on "Remove".
The RECOVERY partition should now be hidden in Explorer.
Select you OS partition, again right click on "Change Drive Letters and Paths...", "Remove" and then "Add" to add the letter C to the partition. If you are not able to choose C restart the computer and try again.
That you will keep the RECOVERY partition. If you want to remove it, go to Disk Management, right click on the partition, and select "Delete volume".
I assume you will want to add that free space to your C (assuming you did manage to chage the drive letter) partition. You can do that by right clicking on the C partition and selecting "Extend volume". I have never done it and would not recommend it. The best thing would be to reinstall the Windows again, and once again create your partitions in the Windows setup.
Only third party software that I would recommend is EASEUS Partition Master. Extending and shrinking the volumes is always a risk! It is safer to do the clena install and configure your partitions during the Windows setup.