Windows Vista crashes, BSODs and general failings.

I'm having a host of problems with my Windows Vista 32bit Home Basic.
I'm on a Toshiba Satellite Pro L40 laptop and have had it for about a year and a half, and the problems are getting harder to bear.
I get regular BSODs - most recently they have been pointing to ntkrnlpa.exe as the probable cause. My system will freeze completely and require a reboot and often, many processes will fail spontaneously - Superfetch, Host Processes and Windows Desktop Manager being the main culprits. I encounter the problems most often whenever I am downloading a file.
Last week, I reinstalled the OS and the problems remain - does this suggest it is a hardware issue?
My specs are:
Processor - Genuine Intel (R) CPU T2130 @1.86GHz 1.87GHz
Memory (RAM) - 1GB
System Type - 32 bit operating system

Let me know what other information I can provide that might help.

Thanks.

 

http://forums.majorgeeks.com/showthread.php?t=35246

 

I did that - it's how I discovered that there is a problem with ntkrnlpa.exe - however, I still am no closer to solving it. I would have thought if the problem remains even after reinstalling the OS, that would be symptomatic of a deeper issue, no?

 

Further blue-screens pointed to memory_corruption as the fault. I upgraded my RAM and the problems persist, with both memory_corruption and ntkrnlpa being blamed. What can this mean?