I have had a first-gen Inspiron XPS for approximately two years.  Recently, I have had an increasing number of problems.  Today when I turned my computer on the taskbar switched from the default windows xp blue to the windows classic style.  Then when I went to change it back, the windows classic style was the only option.  I have also been having an increased frequency of application errors such as:

 

svchost.exe - Application Error

The instruction at "0x8b87bffe" referenced memory at "0x8b87bffe".  The memory could not be "read".

 

I have gotten that error probably 10 times in the past hour.  I also have had a variety of other applications have errors as well.  In addition, for the past month every program I run seems to run drastically slower than when my computer was in its prime.  Are these symptoms of a failing hard drive or is it something else?  Thanks.