Cd/Dvd/cd-rw drive not working when installing windows 8

I am trying to install Windows 8 to my laptop and when I hit F12 on the boot screen, and try to select "Boot from CD/DVD/CD-RW Drive", it doesn't work and just boots Windows 7 normally. How do I install Windows 8 when this happens, or how can I get around this problem?"

My laptop specs are as follows:

-- Dell Studio 17 - 1747 Laptop Genuine Windows 7 Home Premium

-- 17.3 inch HD+ (900p) Bright LED Display with TrueLife

-- Operating System DVD

-- Operating System DVD

-- 500 GB SATA Hard Drive (7200 RPM)

-- 500 GB SATA Hard Drive (7200 RPM) 2nd Drive

-- 1 GB ATI Mobility Radeon HD 4650

-- Processor: Intel Core i7-720QM Quad Core Processor 1.6GHz (2.8GHz Turbo Mode,
6MB Cache)

-- No WWAN Option

-- 125V Power Cord

-- 9 Cell Primary Battery

-- 8X DVD +/- RW Drive

-- Microsoft Works 9.0

-- Genuine Windows 7 Home Premium

-- 8 GB Dual Channel DDR3 SDRAM at 1333MHz (2 DIMMs)

-- Dell Wireless 1520 802.11n Half Mini-Card

-- 90W Adapter