sometimes my computer makes asiren sound consisting of two tones like a french police car. the sounds come from the tower and not through the speakers.  it also seems to occur when the system locks up,but not always.i have had this problem for awhile and have changed my hard drive and my graphics card to no avail.have also added a new fan for cooling.i can usually shut down the computer and let it sit for a while and when it restarts the sound is gone. i have a pc running win 98 with a plentium(sp) I cpu. any ideas will be appreciated. ??

hi
When I turn on my computer, it gives siren sound.

This is usually a power supply or mother board problem.usually its warning of  overheating
Do you get any error messages

BOB

Bob: thanks for the info iwas afraid it might be the motherboard but was hoping it was overheating thats why i added the fans. i up graded everything but the MB so i guess thats next. i'm running a fairly old bios and i'm over due to upgrade the cpu etc. no error messages if i don't shut down right away the pc locks up .thanks again.

Just wanted to add a note since I could not find an answer when I searched before. I was getting the siren sound when some VB applications were getting errors. That can be pretty annoying when you work in cube farm. I found the solution to be to change the BIOS setup (F10 during bootup) to disable the internal speaker.