Macbook only starts into Utilities menu after trying to restore

Question

I recenty bought a macbook pro used off craigslist. I tried to system restore the computer. ( so i could start off with a fresh empty computer) I used disk utility to clear all the memory on the drives, then i proceded to click on the tab that says "install lion osx". Everything started working, but it required me to type in my apple id to complete the instalation. When i logged in it said that my account doesnt have lion bought on it, and i need to use an account that does. I have no clue on how to get lion operating system onto my account without physically logging into my computer and buying it. But since my computer will only start up into the Mac os x utilities menu im not able to buy it.
Help!!!
I want to to a complte system restore

Answer 1

Drive Preparation and Installation
1. Boot from your Snow Leopard Installer Disc. After the installer loads select your language and click on the Continue button.  When the menu bar appears select Disk Utility from the Utilities menu.
2. After DU loads select your hard drive (this is the entry with the mfgr.'s ID and size) from the left side list. Note the SMART status of the drive in DU's status area.  If it does not say "Verified" then the drive is failing or has failed and will need replacing.  SMART info will not be reported  on external drives. Otherwise, click on the Partition tab in the DU main window.
3. Under the Volume Scheme heading set the number of partitions from the drop down menu to one. Click on the Options button, set the partition scheme to GUID then click on the OK button. Set the format type to Mac OS Extended (Journaled.) Click on the Partition button and wait until the process has completed.
4. Select the volume you just created (this is the sub-entry under the drive entry) from the left side list. Click on the Erase tab in the DU main window.
5. Set the format type to Mac OS Extended (Journaled.) Click on the Security button, check the button for Zero Data and click on OK to return to the Erase window.
6. Click on the Erase button. The format process can take up to several hours depending upon the drive size.
7. After formatting is completed quit DU and return to the installer. Complete Snow Leopard installation.