it installed fine but now when I try to boot into it. it has problems.

I already had windowsME.
I have installed Linux Mandrake 8.0
I installed it using the command lnx4win. It installed ok but when I start the computer I am asked to choose out of a few options:
Linux
Linux no fs (I think thats it)
Fail-safe
Windows
Floppy

I choose Linux but then it trys to load then shows the welcome screen (with welcome in a whole heap of languages).
Then has the following text underneath it.
request_module[block-major-7]: Root fs not mounted
VFS: Cannot open root device "707" or 07:07
Please append a correct "root=" boot option
Kernal panic: VFS: Unable to mount root fs on 07:07

Please help I really need this to work.

Try booting with the boot disk that mandrake made you create. You did create one didn't you??????

I'd guess that your problem is that it's not been able to find the root partition as defined by your installation. This could hopefully just be a lilo problem (the boot manager) try and boot with the diskette, and you should be able to get into the system. if you do, run 'mount' from the command line, and it should tell you where the root partition is, ususally /dev/hda5. Make sure this is the value defined in your /etc/lilo.conf file and re-run lilo.

If you can't get in with your boot disk, insert the MDK8 cd again, and run 'linux rescue' to try to access your system. There's a fair few threads about this on here recently, try searching for 'win98 boot' or something simi.lar for details on how to access a linux system that won't load.

oh and linux no-fb (not fs) just means No FrameBuffer. It's just a safer way to control the terminal screen, which is less pretty and useful.

lnx4win is that version of mandrake that installs in the windows partition I believe. You could try to pass a root option to it.
If windows is hda1, try linux root=/dev/hda1 or root=/dev/hda1.