With the SSD attached via a USB adapter right click on Computer and select Manage. Then under Storage select Disk Management. Find the SSD in the bottom pane . Right click where it says Disk 1 (or whatever number it is). What options do you see? Is there one "Convert to GPT Disk" (Probably grayed out)? Should be directly below Convert to Dynamic Disk. If you do not see Convert to GPT (it will probably say Convert to MBR then that's your problem. To verify do the same to the original disk. If it has the Convert to GPT option and your SSD doesn't then it needs to be converted. (If by some strange quirk your original HD is GPT and has the convert to MBR option then you need to make the SSD the same.)
To convert it to MBR:
Start, All programs, Accessories then Right click on Command Prompt and Run As Admin. Type with an Enter after each line:
(Note which disk is your SSD. You should be able to tell from the size and also from the * in the GPT column. I assume it's disk 1 but if not change the 1 to the correct number in the following.)
select disk 1
Go back into disk management and verify that both have the same options.
If it still won't install from the DVD:
Put in the SSD and then go to BIOS setup (F2). Reset the BIOS to Default then Save and Exit. Go back into the BIOS Setup. Does it see the SSD under the hard drives? If not there may be an old IDE option that needs to be changed to SATA. Also make sure they haven't set it to UEFI (if it has UEFI in the BIOS you want it set to Legacy)