I'm assuming your install disk is a retail copy and that you have product key for it ?
Depending upon when you bought it, it may or not include SP1 and for what I propose, it will need to include SP1.
You can check this by tapping F12 as you switch on and use the cursor keys to select the DVD drive - insert the disk and press enter, but make a note of what boot options you have in there and post those.
When the machine boots up, press any key when prompted to boot from CD/DVD.
You may be presented with an inverse window with Windows Setup [EMS Enabled] - just press enter.
I'm not sure at which point the machine will reject the disk as not being the same as the installed volume but if/when prompted, use the dropdown to confirm/change the keyboard input method and click on Next.
It will search for the location of the OS as it doesn't always see it as in C: if that is where it is normally installed, but with yours, I'm not sure.
Make a note of the location and then click on Next.
Select Command Prompt which will be a X: cmd prompt then enter -
bcdedit /rebuildbcd
That will scan the disk for Windows installations and should return as successful.
I only have one main partition on my laptops and that cmd returns Total identified installations : 0
I'm not really sure what yours will return but then enter bootrec /fixmbr followed by exit to close the cmd window - remove the disk and select Restart to see if it will boot properly.
The /fixmbr cmd should return as successful.
However, if it doesn't accept the install disk then you can download an ISO which I believe does include SP1.
I've never been able to confirm this as all my laptops are OEM machines where the OS came pre-installed.
Providing your product key is a retail one, go to
https://www.microsoft.com/en-gb/software-download/windows7 and scroll down to enter your product key and if it accepts it, it will release the ISO for download - select Save.
Depending upon if there was an option in F12 to boot from an USB, you can then use Windows USB/DVD Burner Tool to create a bootable USB - else you will need to get a DVD to create the bootable media.
http://wudt.codeplex.com/As the OS isn't where it's supposed to be, I'm not sure if an offboot sfc /scannow would resolve, but you could try it.
If the bootrec cmds haven't resolved a normal boot, then boot up with the appropriate install disk and navigate back to the Command Prompt.
Using the letter where it found the location of the volume, use that where I've used X in this cmd.
sfc /scannow /offbootddir=X:\ /offwindir-X:\Windows
Note there is a space before each /
This will scan the installed volume against what it has on the install media and repair/replace as necessary.
However, in some cases it will say that it cannot run.