SL does not work anymore

Hi Folks,
I installed SL some days before and everything went fine.
Two days ago, I tried to rund SL with a UMTS/GSM Connection.
It was very slow but began to run.
Then my modem hang up and SL closed because of connection failure.
Since then I'm no longer able to start SL.
The little window appears (detecting hardware) and the it disappears and nothing else happens.
I tried to install SL new first. Then I tried to uninstall SL and install it new. All without success.
what can I do to make it run?

thnaks JohnDoe

Post System Specs Please.

Hi...
I'm using XP-Prof.
Core 2 Duo 2200 with 4GB RAM.
My GC is a NVIDIA Quattro FX 1600M

It seems that SL has broken other parts in my System also because I couldn't run Battlefield 2 any more.
Perhaps this hint helps.

If you need more information, feel free to ask.
greets JohnDoe

Sounds like a driver issue. Do this step by step.
Uninstall your drivers to your graphics card.
Restart.
Install drivers, then update them accordingly.
Restart.
Try to run your games again.

If they do not, then its a different issue (Perhaps DirectX)
But, your card according to the Secondlife FAQ:
"The following cards have not been tested with Second Life, and compatibility is not certain:

NVIDIA cards that report as Quadro
ATI cards that report as RADEON IGP or RADEON XPRESS
ATI cards that report as FireGL
ATI cards that report as FireMV "

Your card seems to be unsupported.
Good luck!

Hi again,
I reinstalled my driver and loaded the actual DirectX from Microsoft.
...without success.

Is there perhaps any Error-protocol that could help?

SL went absolutely fine before this crash.
So my Card was supported inofficial...

thanks JohnDoe

Are you using an Official Viewer?

I'm not sure.
I installed the following file: Second_Life_1-23-5-136262_Setup.exe

This is the only thing i can think of.
Make a new account on your computer with full admin ablilities.
Install secondlife on that account. If it works then its a setting on your other account.

Ok, is it neccessary to create a new account?
I tried Administrator without success.

Do you think the error-logs could help?

From past experience, this is always the best route. If you want to prevent any more unneeded tampering with your system the best thing to do is add another admin account. If the cause of the problem is with settings individualistic to that account, then it should be prominent or the problem should be resolved when you add another.

Ok, fine.
I will try tomorrow, because it's late here in germany...
Thanks for helping so far.
I'll be back.

Hmm...
no success.