Vista Freezing at Start Up...Can this be fixed?

so i recently asked the question here if i would be able to go back to vista using the dell upgrade dvd after uninstalled vista back in march or april....well it was a success...the installing part at least...

 

at first, it seemed vista was actually ok...but then, well, then it happen to me again...

 

when i turn my pc on, the "Microsoft Windows" bar starts to load after the dell screen goes up...after the green bars go by a couple of times, the thing freezes (the green bars) and i have to turn the pc off and turn it back on...

 

IS THERE ANY WAY TO FIX THAT BUG??????????

 

sorry if i'm not too clear about the bug...but again, windows vista freezes at the beginning of the loading process and it never goes past the "Microsoft Windows" bar...

 

might it be my graphics card?

memory?

the processor?

 

the reason i ask this is because the first time around i tried Vista (when it first came out) this was the main reason i uninstalled it and went back to XP...it was just a pain to have to restart the pc and have to turn it back on Safe Mode and then restart hoping it wont freeze at that point...

 

my other bug is...i try playing high quality quicktime videos and they freeze a second into playing. the sound keeps going but the image stays frozen...BUT THE FIRST BUG IS MY BIGGEST CONCERN AT THIS POINT SO IGNORE THIS ONE IF YOU CAN :)

 

any help i can get on what might be causing this freezing would be greatly appreciated! :)

 

here are my pc specs to show what i'm currently running...

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