It is very strange that javascript does not work for you
in K-Meleon and also not in Opera, as you reported.
It could be that your Windows system is damaged.
Go to browser spy with Internet Explorer after enabling scripting,
and test there, if javascript is still not detected.
If scripting does not work in IE, I would presume that
Windows would have to be reinstalled after backing up
your data files.
I would also, before considering a reinstall, check the
computer for viruses and other malware.
Another possibility would be to start a Linux Live CD
and go into the internet with it, to check how javascript works.
A Linux Live CD will not touch your installed Windows,
because it runs completely in ram.
In your case, I would advise for example the new Knoppix 6 in the
small CD version, which is booting very fast into a
text version for people with visual problems.
In the text menu, press 9 to get a command prompt.
and write there
startx
and press the Enter button, to start the normal GUI surface.
Firefox 3 is installed, as far as I remember, under the name
of Iceweasel.
Click on that in the Start button menu, or open a console
terminal and write
iceweasel
and push the Enter button, to start Firefox.
As you try the Linux Live CD, I would also at the occasion
have a look at the other programs, that are already included
by default, as OpenOffice, media players etc.
You could also use K-Meleon, if wine would have been installed
from the repository.
Media players would possibly need installing non-free codecs from
the repository, if they should not be already included in Knoppix.
Knoppix is now based on Debian (they do not include non-free codecs
out of the box), but it is possible, that Knoppix has the codecs
included in the CD already. Installing the codecs is not difficult.
You can download Knoppix 6.0 from here :
http://ftp.tu-chemnitz.de/pub/linux/knoppix/knoppix-cd/KNOPPIX_V6.0-ADRIANE_V1.1CD-2009-01-27-EN.iso
The download is fast and would take about 25 minutes.
You can do other work at the same time.
Then put an empty CD into the drive, and open a burning program
as Nero or similar and burn the live CD.
Do not simply copy your downloaded .iso file to the CD.
This would not work for a boot CD.
Look in the menu of Nero, or what you have, for a menu entry
like "Burn an iso file" or similar.
This would open a dialog box, where you can search for the .iso.
Follow then the instructions, that you burning program gives you
to burn the bootable CD.
When the CD is burned, leave it in the drive and shutdown
the computer.
Restart the computer and the first screen should tell you
the key to press to enter the Boot Menu.
Very often the key is F12, but this can be different for
your computer.
Press this announced key to enter the boot menu.
If it brought up windows too fast , try a restart,
to press the key for the boot menu.
Once you are in the boot menu, select the cdrom as
your boot device. moving the arrow key, and press Enter.
Knoppix would then boot automatically into the text mode,
and you could continue as described before.
This would also be a good opportunity to see what Linux
is as an operating system, without any danger for your
Windows installation.
Regards
Fred