I am sorry to hear that you are having difficulties.
It is not necessarly the speed at which you want to stream but the amount of data you wish to collect when streaming at 10KSamples per second to 100KSamples per second.
If you only have a small amount of ram in your PC and you want to collect more data than you have free memory then the PC will use the hard disk to store the data, writing to disk is much more processor intentisve than if the data is stored in ram.
The fast streaming can also be effected vastly by the USB port if you are using a USB 1.1 I would expect the streaming to be quite limited. It is recommended that USB 2.0 be used.