Glad you got it working correctly.
You are right, you need a system upgrade.
That's not enough PC to run PicoScope 6. Not enough RAM or USB speed. You will be able to do some less demanding tasks with it but you will not be able to go into the high speed streaming modes. The RAM will get used up and the USB 1.1 will also fall down.
Here are the PC resources we recommend at Autonerdz:
Windows XP or Vista 32bit
A processor in the GHz ranges
1 gig of RAM for XP and 2 gigs for Vista (Vista is a RAM hog)
You can revert to PicoScope 5 for now but you will not have the power and features of PicoScope 6. Pico 5 cannot high speed stream and collect over 2 million samples per channel like 6 can. But you won't be able do it with that PC anyway.