Installation error from USB: No device drivers were found

I am reinstalling windows 7 on my laptop. Installing windows is not a new thing for me, as i have done this for a number of times on different laptops. But now, I encountered an error that I never have encountered before.

I made a bootable flash drive and copied all the contents of the iso to it (I have used the same iso since the first time i learned installing windows, so iso should not be the problem). Now, I restarted my laptop and booted it from the flash drive. It then showed the window with the button "install now". I clicked it and the error appeared saying:

"No device drivers were found. Make sure that the installation media contains the correct drivers, and then click OK"
"Load Driver
A required CD/DVD drive device is missing. if you have a driver floppy disk, CD, DVD, or USB flash drive, please insert it now.
Note: If the Windows installation media is in the CD/DVD drive, you can safely remove it for this step."

I believe i have done nothing wrong in my installation process, from making the bootable flash drive to booting from it.

My laptop:
Operating System: Windows 7 Professional 64-bit (6.1, Build 7600) (7600.win7_gdr.120830-0334)
Language: English (Regional Setting: English)
System Manufacturer: ASUSTeK Computer Inc.
System Model: K43SA
BIOS: BIOS Date: 09/26/11 14:41:34 Ver: 04.06.03
Processor: Intel(R) Core(TM) i7-2670QM CPU @ 2.20GHz (8 CPUs), ~2.2GHz
Memory: 8192MB RAM

The error almost always means its a bad installer. Use the ISO for your licensed version from Step 1 written to stick using tool in step 2, then closely follow the other steps to get a perfect Clean Reinstall - Factory OEM Windows 7 which are same for retail.

I have used my ISO before and had successful attempts in installing windows 7 before on my laptop and on other laptops.

Then try writing the ISO to stick again using UltraISO Software To Create Bootable USB Flash Drive
which always works for me. The stick may have become corrupted, needs reformat and rewriting.

Is there a newer BIOS version?

What was wrong with Win7 requiring reinstall?

Where did you get Win7?

seems i had just not copied it the right way. i emptied my flash drive and copied again the contents of the ISO. it works now.

With my laptop Dell Vostro 3560. When I install windows 7 using USB. I go to BIOS and set USB debug to Enable. It's work like a charm !