Vista SP2 Home Premium blue screen

i have recently tried to update my vista to sp2. but after updating it when i plugged anything in usb port . it shows bluescreen error
what could be wrong and solution ?
Answer #1
To find out what exactly is causing a blue screen, you need the code that displays on the blue scree. It looks something like this:
Stop 0x0000000A or IRQL_NOT_LESS_OR_EQUAL
The Blue Screen generates a Minidump File in C:\Windows\Minidump
You’ll need to download and install the Microsoft Debugging Tools to read the Minidump
http://www.microsoft.com/whdc/DevTools/Debugging/default.mspx
and point it to the Microsoft Symbol Server Path:
(that’s the micrsoft server where information on all the latest error codes and whatnot are stored).
SRV*c:\Websymbols*http://msdl.microsoft.com/download/symbols
In the Debugging Tools select: File > Open > Crash Dump
Then you’ll get a report that looks like this:

You can see that the blue scren was caused by Virtual PC.exe.
Answer #2
from where i can point Microsoft Symbol Server Path ?