Limit the memory used by Toad on the Windows machine. One Toad session is using all the memory on Windows machine and impacting other users and sometimes killing the windows machine.
What is the one Toad session doing to use so much memory?
If it's export dataset from a grid, make sure that this box is NOT checked.
More info on that option is here.
Is there anything that we can change at toad configuration level to not to use more than X amount of memory. X for example 2GB or 4GB
You can use 32 bit Toad to limit to around 1.5 Gb (this is a general limitation of 32 bit software). There is no option in Toad to limit the amount of memory that it can use, but I believe you can get 3rd party software which will do that.