Win 7 has crashed several times

Hello,

I have very unussuall problem with my OS.

Starting from Big Bang. I bought my HP Pavilion dv7 laptop on March 2010 with istalled Win 7 Home Premium x64. The computer has been working very well untill summer (August).

One day in august my computer started to be frozen, laggy and very slow. The last thing I remembered was I had installed the 3.6 update for my Mozilla Firefox browser. I have back up-ed my datas and recover the system to factory settings.

The system has been working well until 15th october 2010, when after 3.6 update for my Firefox was done, the black screen of death appeared after reboot (because my system got lagy, lazy and slow again). It was like lightning from the blue. I have lost all my data :-( No safe mode was working. Only black screen with mouse cursor (but the black screen was getting to sleep mode after 10 minutes). When I have started command line, I have realized, that my C: disc is empty. My antivirus havent find any virus before.

Ok. so I reinstall the system again. Last week, my system starts slowly few times (but in other hand, sometimes it was really fast). Since last reinstall, I blocked all possible updates for every software (except Windows). Yesterday, the system was bootin 10 minutes and the blue wheel were still rotating. System got lagy again. So I decided to restart it (the act of clicking to "start button" and confirming restart takes another 10 minutes). After restart, my windows cant boot. The black screen of death with cursor just appear.

But this time, the safe mode is working. All my data are in PC except some photos I have loaded from my camera yesterday (but the directory with smaller version of photos is full - i cant explain why?). But the safe mode is little lagy as well. I have tried to run the regular system and two times it success, but the system was toooooooooo laggy.

As the first time, this happened also as lighting from the blue. I havent installed any updates. Please, what can I do? where can be the problem?

All of my software is legal.
The major software I have installed is:
ESRI Arcgis (cartography software)
MS Office
Mozilla Firefox
Mozilla Thunderbird
WinAMP
Adobe Reader, Photoshop, Illustrator
PDF Creator
ESET Antivirus NOD
CANON EOS Camera system

that´s all.

I hade Win XP before this. I reinstalled it once in THREE YEARS. However the old PC i had were slow, the system was stable. Help me please

Thank you
Voloda

https://www.sevenforums.com/crashes-d...tructions.html
Remove ESET, it is a well know BSOD causer

Maybe I´ve found the solution. Steps I done:

1) Hardly (it takes long time) ran msconfig.
2) Checked selective startup (firstly no checkbox checked, then only startup items and after that only services)
3) Found out that during "only services" startup computer freezes
4) Selected every 10 services and rebooted
5) Found out the 10 services the problem service is within.
6) Tried to able every one of the 10 services
7) Found the trouble-service and disable it

Well, I found, the service called "Windows event log" cause the laggy system.

The startup without it takes at all 1,43 minutes since I push the power button to full start of system-

The startup with it takes 10, 29 minutes since I push the power button to full start of system.

What can I do? It is neccessary service? Why it starts to slow my system one day?