This is going to be kinda lengthy, but I am just going to layout everything as it happened. Thanks in advance for reading. Also, initially this appears to be a hardware question, but ultimately it ends up being about Windows.
I have a machine that has been mostly problem free since I got it a little over a year ago. Over the past two weeks, a few strange things had happened. Windows crashed and upon restarting, it ran scandisk, fixed some problems, and then told me that the prefetch files were corrupted, but everything was now repaired. Everything was okay for a few days. At some point in the middle of something (don't remember what), the mouse and keyboard stopped working properly. They would be responsive for about 5 seconds, then the entire system would hang for 2 seconds and this cycle would repeat itself. With much trouble, I managed to shut down the machine through windows, but it hung on the "Saving your settings" screen for a few minutes, so I did a hard reset. Upon rebooting, Windows again wanted to run scandisk and found some errors, but it then correctly booted and everything was fine for a few days.
Two days ago, things got really bad. I got the same mouse/keyboard stalling problem as above and had to reset. Upon rebooting Windows informed me that "hal.dll" was missing and it could not continue. I went into the recovery console and attempted to copy that file over from my windows cd, but it coulnd't copy. Upon attempting to list the contents of windows\system32 directory, I get an "enumeration error" about half way through the list. At this point, I suspect that the hard drive has problems, so I attempt chkdsk /r. This fails after a few minutes with the "mutliple unrecoverable errors" message. I attempt another chkdsk and get the same result but it took longer for it to fail. Being stubborn, I attempt a third chkdsk and it appears to be going okay after 30 minutes, so I let it sit over night. Upon waking, the chkdsk has completed. I copy over hal.dll successfully and reboot.
Windows boots very slowly (at least 4 times longer than normal) and when I finally get logged in, the same mouse/keyboard stalling problem is present, so I reset again. Upon rebooting I get an error that another file "l_intl.nls" is missing and that I must replace it. Back to the repair console. I replace the file and reboot.
On this try, I am told that "ntoskrnl.exe" is missing. In the repair console, I have similar hard drive problems as I did with hal.dll, it couldn't copy files or provide a full directory listing. I let another chkdsk run and it completes successfully. I then copy the file from the windows cd and reboot. Windows wants to run a scandisk and after getting to the desktop it tells me that the registry was damaged but a backup was restored. Everything appears to be okay.
At this point, I am still concerned that the hard drive might be failing, so I download some diagnostic tools from Western Digital to test it. Upon starting the program, it tells me that support for drives over 137GB is not fully enabled and that it wants to change the registry to allow for full support. The drive is listed at the correct 160GB capacity in Windows, but I allowed the diagnostic program to make the changes it wanted. I reboot and restart the tool. It incorrectly reports the physical drive size as only 9GB, but it correctly lists the logical partition size at 160GB. I don't know what this means. I run the provided diagnostic tools and the drive passes. Although skeptical, I think that perhaps the drive is okay and this whole mess was just a corrupted registry.
I then begin to notice a lot of strange little things. Windows functions fine for the most part, but it obvious that something was lost or broken.
(Problem #1) I noticed that AMD Cool n Quiet is not functioning. I reinstall the AMD drivers and it is still not functioning. I download AMD Dashboard (monitors voltage and clockspeed of your proc) and upon loading it reports that it could not find the AMD ACPI driver. I re-reinstall the driver, but still no luck.
(Problem #2) I begin investigating ACPI related things. I notice that I do not have the option to "Stand by" from the windows logoff dialog, which I used to have. The standby related boxes are missing from "Power Management" settings .
(Problem #3) Upon further research, I end up looking at the Computer section of Device Manager. It lists "ACPI Uniprocessor PC" but there are no drivers installed, which I find intriguing. I remotely logon to my work computer to compare. It also lists "ACPI Uniprocessor PC" but it has drivers installed. Under driver details, three files are listed; hal.dll, ntkrnlpa.exe, ntoskrnl.exe. Two of those files are the ones I had to manually copy over in the beginning of this mess. I don't think this is a coincidence. Selecting Update or Rollback Drivers does not install drivers.
(Problem #4) I do not have the Autoplay tabs under my CD and DVD drive properties. Upon researching this, I learn that a service called "Shell Hardware Detect" must be running for Autoplay to function correctly. I go to admin tools services and see that indeed this service isn't running even though it is set to. I try to start it manually and I get an error that "a module is missing".
(Problem #5) After choosing my logon, the "Loading your personal settings" screen comes up and it takes at least 20 seconds to get to the desktop. This used to take only a few seconds.
(Problem #6) My screen resolution has been reset to 800x600 a few times during a boot.
(Problem #7) Upon shutting down my system, I get the "It now safe to shut down your computer" screen and I must manually turn the power off. Obivously, this didn't used to happen. I haven't seen this screen since I was in middle school on my dad's win95 machine.
I found all those strange problems in just a few hours, so I am confident there are more neat little surprises waiting for me as I use the computer more.
I guess I'll list some system specs and get some of the basic questions out the way. I am using Win XP Home SP2. It is updated and patched. The machine itself is a little over a year old and is built from quality components. I have run AdAware, Spybot, and AVG Free Edition since the bad crash 2 days ago and they reported nothing interesting so I don't think viruses/malware are the cause of this. I can provide any other details if somebody needs them.
OK. Right now, I think that either something bad happened with the hard drive drive itself, that some important important system files were corrupted, or that the registry was damaged, and that in the process of repairing whatever happened (replacing files with ones from the windows cd) some settings or files were lost, broken, or destroyed. Problems #1, #2, and #3 especially lead me to believe to this.
So how do I proceed from here? I really don't know what to do or how to solve these problems. I could do a complete reinstall of windows, but I'd really rather not. How does the "Repair Installion" option from Windows Setup work? Would I lose any data or program information? If I am going to do that, should I just bite the bullet and do a reformat and a clean install? Would it even fix the problems? Supposing that a reinstall isn't an option, what would you guys do?
Sorry for the length post, but I wanted to get out everything that happened and everything I have done. I'd really appreciate any help. Thanks in advance!