Your install disk needs to include SP1 otherwise you will get an error that it doesn't match your volume - or words to that effect and you won't be able to use it.
If you don't have your computer set to boot from the DVD drive first, tap F12 as you switch on then using the cursor keys, select CD/DVD, insert the disk and press enter,
You will be briefly prompted to press any key to boot from CD/DVD - do that.
You may be presented with an inverse window with Windows Setup (EMS Enabled) highlighted - press enter.
Use the dropdown to change the Time and currency format if required - I need to change mine to United Kingdom - click on Next
Click on Repair your computer then make a note of where it locates Windows 7 as it may not always be C: - click on Next and select Command Prompt
Enter (where X is your location letter) -
sfc /scannow /offbootdir=X:\ /offwindir=X:\Windows
For clarity, there's a space before each /
This will take a while to run and doesn't give a % count as it progresses.
Let us know what it reports.
When done, enter exit to close the cmd window, remove the disk and click on Restart.