KERNEL_DATA_INPAGE_ERROR AND SOME TIMES KERNEL_STACK_INPUT_E

DEAR MEMBERS:

I need your urgent hellp to figure out how i can correct these computer errors. I will be informal as much as i can to explain my situation. To start: I have a toshiba satellite 1400-s151 laptop which is 2-3 years old and I have window xp home edition. It never gave me a problem like this...UNTIL NOW. what it says on the blue screen is:

Kernel_data_inpage_error

Then it says if it is the first time the this happens restart your computer

It also says that it could be due to bad installation of hardware and/or software. Ways to fix his is to disable Bios memory options such as caching or shadowing.
oxoooooo7a (0xc0201850, 0xc000000e, 0c042f3860, 0x80614cbb)
The after that it says Dumping Physical Memory.
and underneath that is says something like(didn't quite catch it sorry: atapi-sys-address F9788CA8 base at f9779000 datestamp....(didn't get the last part of the last line sorry


It doesn't show up this blue screen the second i turn it on. FIRST, it gave me this error screen after 5 hours, then it will restart and it will recover (after dumping physcial memory) and windows error report screen will show up and will say:
windows has recovered from serious error (on error report it will say: error signature: BCCode: 7a, BCP1:Co20B1850, BCP2: C000000E, BCP3:80614CBB, BCP4: 0D7A6860
OS ver:5_1_2600
SP:-2-0 Product:256-1
on error report contents from tech info click here:
-the following 2 files will be included in error report:
1. drive c:\Docume~1/Nabeel(user name)\LOCALS~\Temp\wer484.dir00/Mini06305-01.dmp
2. drive c:\Docume~1/Nabeel(user name)\LOCALS~\Temp\wer484.dir00/sysdata.xml

That was just the first time. After a couple of days it got worse by doing a couple of times more and showed me another error which is (not as often as the first):

Kernel_Stack_Input_error
same thing as the first error except it says now:
0X00000077 (0XC000000E, 0XC000000E, 0X0000000, 0X099FD000)


After these, it will show some of kerneldatainpageerror and one more kernelstackinput error. During that time (after 3 kerneldata and 1 kernalstack error), my laptop also starts to make clicking noise never heard before (as if it's writing/reading continuously even if I'm not accessing it) and just as it is doing that after a couple of time my computer will lags and freeze couple of second. After that, my computer just freezes (when the green light is constantly on for more then 10 seconds.) and gives one of the preceeding messages (mostly kerneldatainpageerror).

Therefore, I am afraid it will start to get worse and worse until it will delete every-single-valuable-things from my hard drive! However i am sure one of you kind beings can help me out before it start to do the-most-terrible-thing: delete my entire fuc*** hard drive. (can these two error possible of doing that?)

Before you suggest something know this:
I virus scanned but it found nothing. i also ran regcleaner, tweakregistercleaner but it didn't help either (although it found some stuff often left behind after uninstalling programs), and other spyware programs (ad-aware, spy doctor, search and destroy etc) and got rambooster but none of them seem to help. Therefore, that doesn't seem to be the problem at all. However..

I pinpoint the problem why did it all happened and I came down with 3 things (its only these anyway:)):
1. my first and main suspicion the whole thing started is when my the free download manger encountered a damn BUG. I uninstalled the program but it didn't help (also erased its registry history with regcleaner and tweakregcleaner)
2. I acidently set my externel hard drive one volume (have 3 volume in the external HD) as active, but i dont think that is the problem because i had it active for about a month and during that time it never gave me an error or any of that kind... (again until the download manger encountered a bug but not the problem with the hd just the error)
3. I downloaded 300 files (about 20 mb each) in less then 8 days (i was on trial so during that time i want to downloaded as much as i can so i won't get fully billed ) and it was the first time in those 8 days i used my laptop 16 hours a day. However, again i also don't think thats the problem because i scanned all the files with the virus many times and spyware (the site also has a strict policy on spyware so they couldn't and din't have any, for that i am sure:))

Therefore, I really think its either the bug or the external hard one volume set on active acidently. Therefore, MY REQUEST to my dear member is: Can you please tell me how to fix the bug by what program that does it and how to undo the external hard drive volume as unactive because i don't use it all the time (just to backup files) and just turn it off when i am done. Also, any addition information will definitely help from any of you dear members. so please reply as soon as and as much as you can. I will really really appreciate it!! THANK YOU VERY MUCH! (I will do the same to help you when ever i get the chance.) peace take care!