Dell vostro 400 stays stuck

i have a dell vostro 400 desktop...when i tuen it on it stays stuck on black and blue dell screen for a good 3 minutes...from that screen it gives me the option to press f2 or f12...it wont let me into neither of them...and also when my computer finally boots up i try to go on the internet and it will not let me..i called my ISP and they said its not a problem on their end bc to them it shows i have a perfect connection..i ran all the tests on my pc and its passing all of them. does anyone have a solution for me please?/ its driving me crazyyyy

If it's taking that long at POST, then you likely have a drive port turned on that doesn't have a drive connected to it. Read exactly what is on the screen, as there is more than just "Press F2 or F12". F2 is BIOS setup and F12 is the boot menu where you select a device to boot from. When you have a SATA (or IDE) port enabled with no drive connected to it, the Dell POST sits there and repeatedly tries to find a drive connected to that port. This is why it's taking so long to POST.

As for your internet issue, make sure your ethernet controller is enabled in BIOS and make sure Windows has drivers installed for it. Also check to ensure it's not disabled in Windows.

You need to reset the BIOS. There are instruction in the manual for how to do this.

Disconnect ALL power, network cables, etc.

Open up the case, and find the bios reset jumper. Remove it from the 2-3 pin and insert on the 1-2 pin for about 5+ seconds, then return it to the 2-3 pin.

Power back on. You may have to tell the BIOS not to boot from the floppy and reset your clock, but this should work.