|Use the software the the manufacturer of the internal hard drive. If you don't know what manufacturer it is then download and use SIW. SIW should provide a brand and/or model number. |
Do you have the restore disk for your computer? Imaging is not really necessary if you have some way to re-install the original operating system and bundled software. If you don't have it then you will need to image/ mirror.
There are also third party programs that you can use, including free ones.
Does your external drive have enough room to store everything on the internal drive?
Another option is to image to DVDR using available programs.
Check out the link below. There is a free version available there.