Upgrading to windows 10/Ram compatibility

[Wefro_froyas]

So I have two questions, I am buying new computer parts to upgrade my computer
I am going to buy a copy of Windows 10 and maybe ram if necessary.
My first question is will this ram (from a previous build) be compatible with my motheboard?

RAM:
http://www.newegg.com/Product/Product.aspx?Item=N82E16820231671&nm_mc=AFC-C8Junction&cm_mmc=AFC-C8Junction-PCPartPicker,%20LLC-_-na-_-na-_-na&cm_sp=&AID=10446076&PID=3938566&SID=

Motherboard:
http://www.newegg.com/Product/Product.aspx?Item=N82E16813130731

Also I would like to know how to reuse the hard drive that's already in my computer, it currently has another OS on it and is running on the computer I am writing this message from. I don't know what the steps i have to take to reuse the hard drive and reinstal a new OS

[Geek-9pm]

RAM is not a problem.
Your motherboard will support two hard drives.
You can, if you want to, buy a new hard drive like the one you have. Or even a smaller one.
In the computer BIOS there is some way to select which drive is the boot up drive.
If you buy the Windows 10 disk, you do not have to do the upgrade step. Unless you want to. Even then, you have options.
How To Physically Install A Second Internal Hard Drive

Of course, there has to be enough space inside the box for the second drive. If space is limited, you might pull out the floppy drive and not use it. Who ever does? 

[BC_Programmer]

If space is limited, you might pull out the floppy drive and not use it. Who ever does?

I doubt a system capable of running Windows 10 will typically have a Floppy Drive. For the best, though- Windows 10 literally doesn't support Floppy Drives at all. (OK, that isn't true- it doesn't support Floppy Drive Controllers, so you can still connect USB Floppies)

[Calum]

Long time, no see, Wefro.

RAM: Yes, that RAM should be compatible with your board.

HDDs: Do you want to keep any data from the drive?  If not, just boot from the Windows 10 install media, delete the partitions on the drive during setup to leave a clean drive to install to, and away you go.  If you want to keep any data, the best way would be to back it up elsewhere - onto an external drive for example - and then do as above, just remove the partitions during setup.  It's fairly straightforward to do but if you need any clarification, just say

[Computer_Commando]

I doubt a system capable of running Windows 10 will typically have a Floppy Drive. For the best, though- Windows 10 literally doesn't support Floppy Drives at all. (OK, that isn't true- it doesn't support Floppy Drive Controllers, so you can still connect USB Floppies)

I tested a Win10 install on a machine that happened to have an FDD, Win10 File explorer saw the "A" drive.

[BC_Programmer]

I tested a Win10 install on a machine that happened to have an FDD, Win10 File explorer saw the "A" drive.

Looking into it, they added it back at RTM.

[patio]

Why are you buying Win 10 ? ?