Hi Leo,
Are you trying to do the partition within windows or on a new SSD drive without the Operating System?
Method 1:
If you want to install Windows 7 on a new SSD, 120GB drive is enough to install Windows 7 on it.
I would suggest you to refer the articles and check if it helps.
Create and format a hard disk partition
Formatting disks and drives: frequently asked questions
http://windows.microsoft.com/en-us/windows7/formatting-disks-and-drives-frequently-asked-questions
Method 2:
If you have not created any partition and wants to do it from the boot through a windows 7 dvd, try the steps and check if it helps.
- Connect the SSD to the computer.
- Power on the computer and get into the BIOS settings (For further information on your system's BIOS please refer to the computer documentation).
- If the drive is NOT detected you may need to enable the SATA port.
- Enable SATA AHCI mode (if it is supported).
- Insert the Windows 7 installation DVD, make sure your BIOS is set up to boot from the DVD and boot the system.
- On the Install Windows page, choose your location and language, click next and then click Install now.
- At the which type of installation do you want? screen, choose Custom (Advanced).
- At the where do you want to install windows screen the Windows 7 installation wizard will request from you the disk partition you want to install Windows 7 on. Select the SSD (most likely drive 0) and click next.
- If the drive is NOT recognize you may need install SATA drivers provided by PC manufacturer or by the SATA card controller manufacturer.
- Click next and proceed with windows installation.
Hope this information helps. Reply to the post with updated status of the issue to assist you further.