Windows 7: W7 system: suddenly long boots and periods of ultra slow performance

I have a Windows 7 Professional system running an i7. It was working ok until yesterday. Started by noticing the sound system had stopped working. There was a red X through the speaker icon in the lower right corner. So I rebooted. It went into a chksdk mode (that made me nervous) and then booted but taking much longer than usual. The normal screen eventually came up but the disk access light stayed on for maybe 10 minutes during which I was getting about zero performance. During the boot I got an error message "could not start event service, standard users may not be able to log onEventually the disk access light went off so I tried a few things and the light came back on solid again, stayed on for a numkber of minutes, then went off again. The desktop had changed a little just some changes in the sizes of things and colors. Not sure exactly but the screen just looked a little different.

So something has changed but I don't really know what. I am not sure how to diagnose the problem. While the light is on, I can not bring up task manager.

Things I could try that I know about:
1. I have a disk image from afew weeks ago. I could restore back to that disk image.
2. Try a system restore point. Not sure which ones are in there (PC is at home and I am at worknow).
3. Repair install. I just made a DVD for repaire install.

So i could use some advice on how best to proceed; which order to try things, and maybe there are some things to try not on my list. I ran Hijackthis and don't see anything obvious loading like malware. Just seems like the system is having a problem. Also, I ran Symantec Endpoint Protection, did a full scan last night and it found nothing.

Thanks in advance,
Mark

Your specs show you are using Enterprise and your post states Professional. Just want to be sure what we are working with.
My first choice would be a restore point. At that point because your system has changed and you didn't do the changing I would be thinking of a possible infection. Two programs I recommend and have used.
Windows Defender Offline
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Free Online Virus Scanner | ESET

Pleas let us know if any infection were found and what they were.

Sorry for the confusion. The specs are for my system at work which is in fact Windows 7 Enterprise. When I posted here last year my issue was with my work PC.

Now my problem is with my home PC which is Windows 7 Pro 64 bit.

I was thinking about trying SFC /scannow before trying the restore point.

You think the scan progorams you suggested are worth doing even if SEP (symantec endpoint protection) found nothing? I am happy to do whatever makes sense.

No one anti virus program is a 100%. That is why I use several at times. Malwarebytes Anti Malware is another great program. Something made changes to your computer without your permission. It might of been a innocent program that made a mistake or a bad program trying to mess your computer up. I would never trust just one program to protect my computers. Please keep in mind that only one anti virus program should be install at one time. The programs I have suggested I run while MSE is in use on my computers with no problems. When done you can just remove the programs you don't want.
At this time I run
MSE active
MAM Pro active
SAS on demand
PSI 3.0 on demand
Filehippo Update Checker on demand
Windows 7 built in firewall
About every 4 to 5 weeks I scan with ESET. If any problems are found I use Defender Off Line. I check Windows Updates 3 to 4 times a day.
------------
This is what you don't want to have to go through and it was caused by a false positive.
Help with Zbot infection.

I ran sfc /scannow and it found two corrupt files. I went through the manual extract and replace process, ran sfc a second time it the same two files are corrputed. I rebooted and ran sfc a third time and the same two files are corrupted. I potsed the most recent lof file section below. How come if i replace them and recan they are still corrupted?


2012-11-20 18:42:14, Info CSI 000002f8 [SR] Cannot repair member file [l:28{14}]"powershell.exe" of Microsoft-Windows-PowerShell-Exe, Version = 6.1.7600.16385, pA = PROCESSOR_ARCHITECTURE_AMD64 (9), Culture neutral, VersionScope = 1 nonSxS, PublicKeyToken = {l:8 b:31bf3856ad364e35}, Type neutral, TypeName neutral, PublicKey neutral in the store, hash mismatch
2012-11-20 18:42:36, Info CSI 000002f9 [SR] Cannot repair member file [l:20{10}]"wscsvc.dll" of Microsoft-Windows-SecurityCenter-Core, Version = 6.1.7601.17514, pA = PROCESSOR_ARCHITECTURE_AMD64 (9), Culture neutral, VersionScope = 1 nonSxS, PublicKeyToken = {l:8 b:31bf3856ad364e35}, Type neutral, TypeName neutral, PublicKey neutral in the store, hash mismatch
2012-11-20 18:42:36, Info CSI 000002fb [SR] Cannot repair member file [l:28{14}]"powershell.exe" of Microsoft-Windows-PowerShell-Exe, Version = 6.1.7600.16385, pA = PROCESSOR_ARCHITECTURE_AMD64 (9), Culture neutral, VersionScope = 1 nonSxS, PublicKeyToken = {l:8 b:31bf3856ad364e35}, Type neutral, TypeName neutral, PublicKey neutral in the store, hash mismatch
2012-11-20 18:42:36, Info CSI 000002fc [SR] This component was referenced by [l:242{121}]"Microsoft-Windows-Client-Features-Package~31bf3856ad364e35~amd64~~6.1.7601.17514.Microsoft-Windows-Client-Features-Update"
2012-11-20 18:42:41, Info CSI 000002fd [SR] Cannot repair member file [l:20{10}]"wscsvc.dll" of Microsoft-Windows-SecurityCenter-Core, Version = 6.1.7601.17514, pA = PROCESSOR_ARCHITECTURE_AMD64 (9), Culture neutral, VersionScope = 1 nonSxS, PublicKeyToken = {l:8 b:31bf3856ad364e35}, Type neutral, TypeName neutral, PublicKey neutral in the store, hash mismatch
2012-11-20 18:42:41, Info CSI 000002fe [SR] This component was referenced by [l:242{121}]"Microsoft-Windows-Client-Features-Package~31bf3856ad364e35~amd64~~6.1.7601.17514.Microsoft-Windows-Client-Features-Update"
2012-11-20 18:42:41, Info CSI 00000300 [SR] Repair complete
2012-11-20 18:42:41, Info CSI 00000301 [SR] Committing transaction
2012-11-20 18:42:41, Info CSI 00000305 [SR] Verify and Repair Transaction completed. All files and registry keys listed in this transaction have been successfully repaired

Hi rhodesengr,
Just to rule out a defective hard drive as you had very long disk accesses and are getting corrupt files. Download this program Hard Disk Sentinel - HDD health and temperature monitoring
(free trial) and it will report on the health of your drive.
If you have a rapidly failing drive it will cause these symptoms.
Good Luck
Tony.

Other Troubleshooting Steps for Windows 7

If you lose boot: Troubleshooting Windows 7 Failure to Start

so I ran hard Disk Sentinel. This what i got. So it does look bad for the HD. So the full story is that my HD failed about a month ago and my local shop installed this new one. So this is basically a new drive. There was some other issue with bad sectors so I had run chkdsk /r and I thought that might have fixed it. I ran the WDC utility and it failed that test. I guess I should take it back. What do you think?
The drive found 658 bad sectors during its self test

e are 490 weak sectors found on the disk surface. They may be remapped any time in the later use of the disk.
At this point, warranty replacement of the disk is not yet possible, only if the health drops further.
It is recommended to examine the log of the disk regularly. All new problems found will be logged there.

Yes, taking it back it is on its way out. I have seen this several times before. Print off a copy of the report for them. 8% is bad. I have never had a false report with that program and I respect the author for a great tool.
That drive cannot be trusted. Make sure you have a back up of all your "stuff" on that drive.
47C is warm too unless you are in a warm part of the world. The warmest one I have runs at 41C having been on all day. Also of note a "NEW DRIVE" with 292 days use on it??
Tony

I am still curious why replacing the bad files did not fix the bad files. Shouldn't replacing them have fixed them?