can i make the total disk storage of 2 hard disks as one to be shown

It`s fine to have logical partitions, personally, I don`t recommend it.

Did you change something, it`s not supposed to go to the computer properties page unless you right click on computer and choose properties.

You can change drive letters in disk management if you really want to.

yes you can change them, but why bother ? There`s no reason they can`t be primary partitions.

It supposed to go to that page.

What you want to do sounds like changing the discs from basic to dynamic, you don`t want to do that. I`m no expert on that, just don`t do it :)

How to Combine Multiple Hard Drives Into One Volume for Cheap, High-Capacity Storage

Why not just use Windows Libraries? I do not recommend spanned volumes or RAID (RAID 0 is the only RAID that would give you the results you are looking for); both are too risky. Lose one drive and all your data goes south. They are also harder to backup (keep in mind that RAID is not a backup).

In a nutshell, RAID is an acronym for Redundant Array of Independent (or Inexpensive, depending on which expert you believe) Disks. RAID was developed back when HDDs were much smaller and slower than they are now to speed them up, create redundancy to help prevent data loss should a HDD in the array die, and/or increase their volume. RAID 0 both increases the speeds of the disks in the array (RAID 0 is the only non-nested RAID that will speed up disks; the others actually slow them down)and makes them appear as a single volume. The main danger of RAID 0 is it has no redundancy; if a disk should die, data will be lost from all of the disks. Essentially, RAID 0 both increases the danger of data loss and the amount of data that gets lost by a factor of the number of disks in the array. Two disks in RAID 0 will be twice as likely to fail with twice the data loss, three disks would have three times the risk and damage, and so on and so forth.

Raid 1 is also known as mirroring. Basically, a disk in RAID 1 will automatically create a copy of itself on another disk. Many people feel that RAID 1 is a good backup. While RAID 1 will help to prevent data loss if one disk should fail, disk failure is not the only thing that can cause data loss. Data corruption caused by a virus will be replicated on the mirror disk. If you accidentally delete a file on the disk being mirrored, it will also be deleted on the mirror.

Other forms of RAID, such as 5 and 6, distribute data in stripes across multiple disks with each stripe being duplicated on at least one of the other disks in a way that if one disk in RAID 5 or up to two disks in RAID 6 should fail, no data will be lost and, when the failed disk(s) are replaced, the RAID will rebuild itself. As in RAID 1, this ensures continuous operation without data loss due to disk failure but is also subject to data loss from other factors.

For anyone other than a business that cannot tolerate an interruption in operations, RAID of any kind is not really necessary. There far safer ways to backup data and create single directories.

Other that to separate system files (OS, programs. etc.) from data when sharing a single disk, partitioning is also unnecessary and is an extremely inefficient way to segregate and/or organize data. Windows folder/file system is far more efficient.