So I have recently begun building my new computer, and without thinking got through the entire build without even thinking of what was on my HDD and SSD. Basically both have all of my work and files and neither are backed up (oops) though I could quick pop them into a different computer and copy the bare essentials. But the most important part: I have Windows 7 installed on my SSD and my question is thus:
-With Windows already installed on the SSD will I be able to start up the computer without a re-install?
-and if not will reinstalling windows in the BIOS corrupt any of my existing data that is contained within the SSD?
You likely will not be able to boot off of the same HDD on a different computer as all of the drivers will be completely different. An external HDD enclosure will work to copy your files onto a new drive, or install windows on one HDD, then copy the files over from the SDD onto the HDD. Install Windows on the SSD and move the files back over.
Because windows is installed, the computer can read it no problem, just might not be able to boot with it. (Theoretically).
Let's think about your question. On your SSD you have your old OS install. During the install process it detected all your hardware and installed at the very least generic drivers for each one. Then you installed custom drivers for specific hardware and updated them since the original install.
Now you have put that SSD into a new box. When you boot, it will:
Try and load drivers for hardware that it can't find.
Won't be able to find drivers for hardware it does find.
The more new that isn't the same as the old, the more borked the system will be.