iMac beeping & flashing

[toffeepop]

HI Guys.
Apologies if I am posting in the wrong area, but I am new here.

A week ago my iMac, on start up flashes the "disk inserted is not regonised" warning, but it flashes up quickly, like a strobe, along with a beeping sound.
I have to keeping clicking the mouse on Ignore and just hope it will connect, and then it stops.
I am pretty sure it is connected to my wireless modem, but I have no install disk or anything with it, so not sure what to do to stop it.
Also once I have actually connected to get online, if I try and scroll to one of my bookmarks in my tool bar it won't let me... It will just start up the very top thing that's in my toolbar.
I hope I am making sense.... any help would be great.
Thank you...

 

[chscag]

We need some more information. Is there a disk inserted in your iMac when you get the message? (Check to make sure a disk is not stuck in the drive.) Or is it doing that whether there is a disk loaded or not?

I'm not sure what that has to do with your wireless modem? Please explain further. Also give us some details about your iMac. Year, model, and which version of OS X you're running.

 

[toffeepop]

I am using a 2007 iMac running 10.5.8 version of OS X.

I am pretty sure its the USB modem that's causing the "the disk inserted..." warning as it only comes up when the modem is plugged in.

Thats not really my problem, the problem is the constant beeping and the flashing of the warning. And also not being able to scroll into anything in my toolbar.
I also can't access my console (apps>utilities> console) it keeps saying Not responding.