Boot manager not showing

[AhmadRazasayyal]

Hi Guys My name is Ahmad I m from Pakistan. When, I insert DVD, CD in my cpu or boot able USB connect to my cpu and restart the computer but press any key to from keyboard is not showing and old window is start please help me

[Lil_Boy_Blue]

Hi

Is it one of these? 

HP Pro 3500 Microtower PC

https://support.hp.com/us-en/product/hp-pro-3500-microtower-pc/5270849

[AhmadRazasayyal]

Yes but how can I repair this?

[Lil_Boy_Blue]

Hi

Well the link I gave holds lots of answers, how you repair it I don't know.

Me? I would refer to the manual for clues.

http://h10032.www1.hp.com/ctg/Manual/c03550748

Page 7  Computer Setup (F10) Utilities

Use Computer Setup (F10) Utility to do the following:

Change factory default settings.

Set the system date and time.

Set, view, change, or verify the system configuration, including settings

for processor, graphics,memory, audio, storage, communications, and input devices.

Modify the boot order of bootable devices such as hard drives, optical drives, or USB flash

media devices.

Page 12 Boot Order.

Page 176   System will not boot from CD-ROM or DVD drive.