Although Windows 10 has several advanced functionalities than the earlier versions some changes are not as desirable. The slider volume option with its volume mixer settings for instance is absent in the Windows 10 version.
If you wish to get this particular feature from Windows 7 or Windows 8 version you can create or alter the registry key. Here are the steps to follow:

Step 1
Open Registry Editor by pressing the 'Windows' key or entering the words ‘regedit’ in the search bar of your computer’s start menu and press enter.

Step 2
Use navigation pane present on the left side of the window for browsing the folder below: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion

Step 3
Now add or change the registry key by using right click on the 'Current Version' key and choose New> Key option. Name the version as 'MTCUVC' and hit the enter key.

Step 4
Choose 'MTCUVC' key present under Current Version and right click on right side panel. Choose New>DWORD (32 bit) Value option.

Step 5
Assign 'EnableMTCUVC' to the value and fix the data value to default as 0.

Now close the window and click on the speaker icon in the desktop page. You will find the earlier volume control version. And you need not reboot the system to enable this change. If you want to return to the new volume version go back to the registry editor and right click on ‘EnableMTCUVC’ value you had created and remove it.