Can't boot windows for reinstallation

Hello,

i have this serious problem and wish somebody could help me resolve this..i wish to reformat and reinstall windows 7 starter to my computer. its been a while already since i've noticed my pc does'nt work properly, very slow performance, always gets hang and so that why i decided that might reformating can help fix my computer. i am not really into particular with system troubleshooting i only depend my knowledge searching through net.

i have a genuine dvd installer for windows 7 starter (borrowed from a friend), i searched deeply through net how to install and reformat and found some from youtube. i shut down to notes all the information there and performed it by myself. i first inserted the cd installer and restarted, when it came up to the boot menu, there it appears on screen ;

== select a boot first device ==

-> REMOVABLE
- floppy disk
-> HARD DISK
- ch2 M.: Maxtor Stm *******
- bootable add-in cards
-> CD ROM
-> USB-CD ROM
-> LAN


I chosed then the "CD ROM". knowing then also from others that there must have appeared there a "DVD/CD ROM" and select but theres non. after i selected it (CD-ROM), i clicked enter then wait to load, the problem then arises.. the system loaded just like its normal loading condition as to start the system up. it never initiated any installation process.
from there i assumed that my dvd writer must have been defected, because i tried also other dvd's ,movie dvds ,cd's and others to the drive and it seemed never worked out, just nothings happened, nothings appeared on screen, no notification at all.

i might could have used an external dvd writer but i am trying to look for a solution to this without the use of any external alternatives because i dont have yet any external dvd writer to use.

anyone can help please?. this is my first to perform a reformat and i'd love to extend my knowledge through your help.. please any helpful information is very much appreciated. thanks ...