Software Issue or Hardware?

My Question is regarding the issues im facing with my display adapter which
is Nvidia geforce 7600 im using HP pavillion notebook dv9335nr .the issue
with me is that after some time my computer screen freeze's and restarts
after restart i see multicolored lines which are vertical and are in red and
white colored striped lines and it also doesnt let me access my OS which is
Vista home premium 32bit version.it has been really confusing for me because
right before the restart of my p.c i get this blue screen error explaining
that the computer has been prevented from serious damage and all.though im
able to use my notebook via the VGA adapter but not the nvidia one.but if i
try to install and uninstall my nvidia driver 2 to 3 times then again
everything works fine but after some time same problem screen freeze's and
gives weird multicolored lines ,and computer restarts with the same red and
white vertical lines all over due to that it doesnt go to OS and i get this
bluescreen error!.......what this could be this has been happening since last
4 to 5 days and im quite confused about this because thats the only p.c i
have and i work with it all the time please do let me know if this issue is
related some software issues by vista OS or its my hardware which is nvidia
geforce go 7600!