IF you generate these two log files and post it somewhere for me, I can tell you exactly why it runs slow. Some will be high probability, background indexing or security scans, others may be rogues.
http://www.geekstogo.com/2010/05/27/otl-by-oldtimer-a-modern-replacement-for-hijackthis/
I've done this hundreds of times so I can read these logs.. Not for the newbie to analyze, but anyone can run it. ITs called OTL.exe
added
My usual findings are excessive slugware or good programs when used in combinations of certain others, make a quad core tower into a dinosaur at times. One of the biggest slugs can be in some cases, using >1MB host files which are readin periodically into separate memory caches by EVERY active app. that uses web for updates or has firewall privvies. This in combination with the File INdex service plus a massive AV solution with a 4 or more services. I have solutions to all of these and hundreds of more reasons why OTL.exe can tell me exactly what is slowing down your PC. BTW. The Task mgr only records a snapshot of CPU useage every 15ms and apps which run short threads and exit or use hidden features or consume a lot of hidden time in maintenance are not recorded in Task Mgr. Hence 2%cpu usage means nothing. There are better tools , procmon.exe , Mark Russinovich® free tool, being one, to see what is happening. I digress but can prove what I promise.
I will reply with a list of suggestions and recommendations for you to fix your own PC and learn why / what/ how to make and keep it screaming fast and stay secure.
Disk errors can easily be found in the System log file. BLoated or corrupt MFT's or backup $mft files can be bloated or corrupt can contribute to delays and remedied with run> chkdsk /f (y on reboot). But none of these are sufficient to explain your symptoms on their own.
Msconfig.exe is a primitive tool that just scratches the surface and does not show hidden files, processes, services or rogue drivers, rootkit, or bootkits.
THe choice is yours. Trial and error or get help from a Windows expert.(moi)
Update 5/25
Having reviewed your OTL.exe log files, the results have raised a few questions in my mind, but still no certainty to actual random system stalls at your end. I can indicate few high probability areas of high risk. Further feedback from you on when this starte and how often it occurs will help me.
Generally, you have evidence of reasonable security and evidence of common insecurities.
Security minded Apps
- Microsoft Security Client
- Windows Defender
- Avast
- SpyBot
- PeerBlock
Unknown traffic load
- LogMeIn
- FileZilla FTP
- PowerIso
- Dropbox
- uTorrent
There are a few other startups that may be sluggish but.... since this was a clean install of Win7x64 on May 13th, when did it behave acceptable last ?
4random freezes point to hardware failure, most likely ram. i also think your "it runs slow because of defragmentation" was a wrong conclusion, defragmentation is not really a problem under win7. check your hw. – akira – 2012-05-22T06:01:10.347
is this happening after you reinstall your OS? – blasteralfred Ψ – 2012-05-22T07:08:39.917
Does this serious lag also happen when in safe mode? – Arvanitis Christos – 2012-05-22T09:33:42.407
You can also use a tool like HDTune to examine the performance over the full length of the disk. You are looking for large dips, or a very erratic line which would indicate you either have a poor quality or dying HDD. The kinds of numbers to expect for a single 7400RPM drive would be ~80-130MB/s read and ~10-15ms access time, if you've got RAID or an SSD then its a whole other kettle of fish (and a different set of trouble shooting).
– Turix – 2012-05-22T10:02:45.250Be sure to run the tests DURING slow moments - they won't help if they seem to run normally since you would not know which device is not performing optimally. – netrox – 2012-05-23T16:27:53.540