Before you can use your new SSD you have to initialize and partition it.
Attach the SSD as a secondary drive and load Windows from your existing drive.
In Windows 7 and earlier, open 'Disk Management' by right clicking on 'Computer' and selecting 'Manage', then 'Disk Management'. In Windows 8 and later, move the mouse to the lower left corner of your desktop and right-click on the Start Icon, then select Disk Management.
When Disk Management opens, a pop-up should appear and prompt you to initialize the SSD.
Select MBR (Master Boot Record) and click OK
Right click in the area that says Unallocated and select New Simple Volume...
The New Simple Volume Wizard will open, click Next
Leave the Specify Volume Size as the maximum (default value) and click Next
Select a Drive Letter and click Next
In the Format Partition screen, decide on a Volume label (the name you want to give the drive) and click Next