System hangs when connected to dataone broadband

[hsmukunda]

Hi
I have a particular problem.Operating system is windows 98. I can only connect to internet either in 16 colors or 256 colors display.
When I switch to 16 bit true colour or 32 bit true colour display, connect the modem and click on internet explorer the monitor goes black and then the system hangs.
I cannot even open my admin page for my dataone modem in 16 or 32 bit display.
If I try opening display settings in 16 bit or 32 bit display I get a blue screen.
I formatted the whole drive and installed 98 newly but still the problem.
I even checked whether is this an irq problem but nothing as such.
Even checked with drivers all of them are working.
The modem I am using is type 2 modem of bsnl or UT starcomm with one port for ethernet and other has the wireless.
What could be the problem, hope some body might be knowing why is this happening like this.

thanks

[Sawmendra]

System config plz.

In bios check the amount of memory allocated to vga. If it's less than 32 MB try 32-64 MB If u have 128 MB or above RAM.
If u can get a spare PCI vga card from some where try with it.