problem installing 10.0_modelsim_ase_windows

I now re-installed nios, modelsim, and quartus 91.sp2 and no problem. Then I removed them all with ControlPanle->Add or Remove Programs. Did a restart. Then tryed to install inn the following order:

10.0_quartus_free_windows.exe "innstalled passed"

10.0_nios2eds_windows.exe "installed passed"

10.0_modelsim_ase_windows.exe "installed failed"

The note I get with the Installation Failed is:

ModelSim-Altera Starter Edition (Free) installation failed.

Incomplete installation File 'c:altera\10.0\modelsim_ase\..

\modelsim_ase/win32aloem/instanceguid.txt' does not exist.

It is a bit supprising to see the switching of \ and / in the path... but this is how the error looks like..

now if I try starting quartus, modelsim or nios2eds then it starts browsing for missing shortcut...