In the first set of install options the only logical choice is "something else," but then the 2nd set options skip disk 'a' that I want to install too and presents partitions for disk 'b'; then the field below has written in already to make changes to disk 'a' but when I press "continue" it doesn't make sense for me. Seems to me the install program is missing some logical options along here somewhere.
What I want to do is end up with the following partitions on disk 'a', a 500 GB HDD that contains windows 7, which I wish to retain:
• Boot, 250 MB, Primary, Ext 2, /boot
• Root, 20 GB, Logical, Ext 4, /
• Home, 150 GB, Logical, Ext 4, /home
• Swap Area, 6,144 MB

If I manually create those, how do I get the correct files into each partition?

Better start with a backup of windows 7.

"If I manually create those, how do I get the correct files into each partition?"

On many installers you have a way to create your partition choices. You have to be careful at this point to tell the installer what the mount point of each partition is. Some installers are quite difficult to force but you can try. Also some installers won't fully create the partitions and let you install as it seems to lock the changes. May have to use a live distro to create these choices and then reboot into the distro installer.

/boot will be assigned to some reference that is your 250MB partition and so on down the line. This is where the installer needs to know what is what. You assign /home and /boot and /swap to where you want it to be. Actually /swap usually just does it on it's own if it finds it.

How many partitions do you currently have for the already installed windows 7 on the drive on which you want to install Linux Mint? Do you have any unallocated space available on which to install Mint? If you want help, you need to post some specific drive/partition information which you can get by booting the Mint DVD and opening a terminal and running the following command and posting the output.

Lower Case Letter L in the command.

Thanks for the response; it is indeed appreciated. Disk 'a' is 500 GB; 195 GB is partitioned for Win-7, the rest is UN-allocated; the other 3 disks are for: programs, documents, backup.

If you have over 300GB of unallocated space, there should be no problem using that to create the partitions you want if in fact, windows 7 is only using one partition which you don't explain. That would be pretty unusual because windows 7 usually has a separate boot partition as well as at least a recovery partition.

You forgot to post the fdisk information.

Once again, I want to thank you for taking the time and effort to try and help me. I tried to give you, what you asked without burdening you with a lengthy, rambling, irrelevant explanation. I was aware that I had sufficient disk space for Linux. Here is the exact description of disk 'a': It is a 500 GB capacity drive divided into two (2) partitions: 1) a 195 GB primary, boot-able partition for Win-7, and 2) a 270 GB extended partition that is un-allocated. I have no problem manually creating the partitions I want to use for Linux. My question is: How do I get the correct files into each partition? I have been fooling around with Linux from time to time since 2012, but have never gotten it installed on a HDD, just too many installation frustrations. I think Linux in the latest Mint version is a big improvement. I also think the reason the majority of America isn't using Linux is because of its installation program/procedure requiring so much background knowledge and the installtion procedure/program being so frustrating to work with. I don't like having to ask for help, but I guess it's time, and I do indeed appreciate those who are willing to give a little. Cordially, Jerry