No more sound in the preview

Hi.

I've got a strange problem in mmf:
when I do F8 or F7 to have a preview, I can't hear any sound. When I do an app, the sound work correctly. How can I fix this problem?

I've had this problem before, and it was unable to be fixed. But after getting a new computer, suddenly it works again.

I'm curious to know:

A) Do you have Norton?
B) In the MMF2 folder there is a Filters folder. What's in it?
C) Does the sound work if you try HWA?
D) What build are you using?
E) What OS are you on (and perhaps some more details about your computer?)

I had Norton and the problems started occurring after using it so it makes me wonder if it's part of the problem.

First, you have to know that it used to work before (yesterday mmf was working perfectly).
So, I give you my answers:

A) No, I haven't got Norton. I'm using Mc Afee but I'm going to use Nod32.

B) There is the folder "Sound" with-> aiffflt.sft ; modflt.sft ; oggflt.sft ; waveflt.sft

(The folder "images" with-> aviflt.ift ; bmpflt.ift ; fliflt.ift ; gifflt.ift ; jpgflt.ift ; pcxflt.ift ;pnfflt.ift ; tgaflt.ift)

C)The sound work with mmf HWA

D)I'm using the version 2.0 (Build R249)

E) I have Windows7 64bits. (Pentium Dual core 2.10GHz x2; 4GO RAM)

I'll change my antivirus, maybe that will fix the problem...

No it might not. It's a weird problem. (I disabled Norton and the problem remained)

Check the mixer settings immediately after running the preview. Is the volume at zero?

All your sound filters are there. Maybe a virus got into sound drivers?

Yeah !
It's a lucky day ! Sound came back today :)