I've been having this problem for quite some time now where suddenly the computer crashes and i get the blue screen of death and it shuts down after about 20 mins of use. i've tried as you suggested to re-install the driver before use but this only works sometimes but more often than not the blue screen of death appears. do you have any other advice other than re-installing the driver each time.

Guarantee you its a bad hard drive.

Have you analyzed all your files and deleted all the corrupt ones?

A blue screen of death will only occur as far as Scratch Live is concerned, if you don't have the proper driver installed.
If that is the case then you'll get a blue screen every time you shut down SSL.

Look to see what driver number you have installed.

1. Click on the start menu.
2. Right click on 'Computer'.
3. Click on 'manage'.
4. Click on the 'device manager'.
5. Click on the + sign next to 'Universal Serial Bus Controllers'.
6. Right click on the 'Serato USB device'.
7. Click on 'properties'.
8. Click on the 'Driver' tab.
9. Look at the 'driver version'.

The version should be 1.2.2.

If you do have that version installed then the blue screen will be due to some hardware failure and I would get your computer looked at by a professional.

i have version 1.2.2 any other suggestions?

Then the issue isn't going to be Scratch Live related.
I would suggest getting your computer looked at by a professional.