Windows 7: Chkdsk Accidentally deleted an important .dll file

Here's my situation after running a memory test my PC restarted and then went to Chkdsk. After scanning in Stage 1, It scanned the index files if I can remember and then it showed that "something"explorer.dll is unindexed. Chkdsk tried to find the host but it didn't find it and it was deleted. After that my PC restarted and then on log-on screen during "Welcome" a popup appeared saying "something"explorer.dll is missing and after "Welcome" its was all black. I tried to run taskmanager and then manually started explorer.exe but "something"explorer.dll is missing. I system restore my PC and it worked properly explorer.exe is working fine now. Its ok now that its works normally now but what will I do to prevent Chkdsk deleting that .dll file. I don't have a recovery disk. Also I wrote this thread during safe mode so I can make sure that everything is working fine for now.
System Specs:
OS: Windows 7 Home Basic 32-bit (6.1, Build 7601)
CPU: Pentium® Dual Core CPU E6700 @ 3.20 GHz
Memory: 2048 MB RAM Samsung 2rx8 PC3 10600u
GPU: Intel® G41 Express Chipset
HDD's: Seagate Barracuda ST3320418AS 320 GB (The drive that was Chkdsk)
Western Digital 32000BEV External HDD 298.09 GB

Chkdsk has messed me over pretty good a couple times. I try to avoid using it at all costs.
my 2 cents.

I don't want to avoid chkdsk, I just need to find a fix so chkdsk won't mess up with important .dll files or other OS files. If its unfixable then avoiding chkdsk is the only way.

I wish I wouldn't have to avoid it either, but after I ran it and it ended up deleted my entire hard drive, I decided I would never use it again and I will find a work around.

I am still not 100% sure what caused it but getting out of a shower to see your Chkdsk deleting all of your files (after the reboot) is not a good feeling. It should never happen, ever. After that I have never used Chkdisk for anything and find a work around to my problems.

Also: If anyone can tell me why they think this happened to me, I would appreciate it, thanks.

I doubt that check disk is your problem, but rather either malware or hardware failing or corrupted system files. Try running a scan with a reputable AV and MalwareBytes AntiMalware.

HTH

My scan is done and my PC is clean also before chkdsk stage 2 of 3 there were no bad sectors scanned in my HDD. And if hardware failing would it be the HDD first because when I use my PC the temperature of my HDD is around 37-42 C° . And if its corrupted file systems will it be the registry or the HDD ?
Also the .dll file is explorerframe.dll.

I also made a back-up of files a year ago (I don't know what files are back-upped, But I think all the files were back-upped.), will it solve the problem?

At this point, I would say the system appears to be OK. Did you recently download any Windows themes?

You could also run:

• Anti-rootkit utility TDSSKiller

To see if there are any hidden rootkits within your system, which may be undetected from the anti-malware scan.

@Sir George: I downloaded dreamscene seven but it wasn't installed because no Aero themes were detected. My UI, Welcome screen changed from usual dark to light gradient to that Welcome Screen. And asked my self why I thought that it was an update but there were no updates that day.
@x BlueRobot: Those are the results, What should I do?
*I was on safe mode because of BSOD's happening while on normal mode.