My Macbook Pro 17" Late 2008 OS X 10.8.5 keeps freezing after some flickering

What can be the problem and how to fix???

It started last night and keeps freezing just a few minutes after starting.

Mouse & cursor move ok, but can not click anything.

Right now it's working longer than usual, so I hope can finish this post...

Lower half of my browser is changing from white to grey every second or two.

Please help!!!

Results of EtreCheck:

Hardware Information:

MacBook Pro (17-inch, Early 2008)

MacBook Pro - model: MacBookPro4,1

1 2.5 GHz Intel Core 2 Duo CPU: 2 cores

4 GB RAM

Video Information:

GeForce 8600M GT - VRAM: 256 MB

System Software:

OS X 10.8.5 (12F45) - Uptime: 0 days 0:7:12

Disk Information:

Hitachi HTS542525K9SA00 disk0 : (250.06 GB)

disk0s1 (disk0s1) <not mounted>: 209.7 MB

Untitled 1 (disk0s2) / [Startup]: 149.48 GB (26.02 GB free)

Recovery HD (disk0s3) <not mounted>: 650 MB

DATA (disk0s4) /Volumes/DATA: 99.58 GB (9.42 GB free)

USB Information:

Apple Inc. Built-in iSight

Apple, Inc. Apple Internal Keyboard / Trackpad

Apple Computer, Inc. IR Receiver

Apple Inc. BRCM2046 Hub

Apple Inc. Bluetooth USB Host Controller

FireWire Information:

Thunderbolt Information:

Kernel Extensions:

com.magican.iokit.netmon (1)

com.magican.iokit.filemon (1)

Problem System Launch Agents:

[System] com.paragon.NTFS.trial.plist 3rd-Party support link

[System] com.paragon.NTFS.upd.plist 3rd-Party support link

Launch Daemons:

[System] com.adobe.fpsaud.plist 3rd-Party support link

[System] com.anchorfree.ajaxserver.plist 3rd-Party support link

[System] com.google.keystone.daemon.plist 3rd-Party support link

[System] com.magican.castle.plist 3rd-Party support link

[System] com.microsoft.office.licensing.helper.plist 3rd-Party support link

Launch Agents:

[System] com.google.keystone.agent.plist 3rd-Party support link

User Launch Agents:

[not loaded] com.adobe.ARM.[...].plist 3rd-Party support link

[not loaded] com.apple.CSConfigDotMacCert-[...]@me.com-SharedServices.Agent.plist

[not loaded] com.facebook.videochat.[redacted].plist 3rd-Party support link

User Login Items:

iTunesHelper

Dropbox

MagicanMonitor

Hotspot Shield

Internet Plug-ins:

Flip4Mac WMV Plugin: Version: 3.1.0.24 - SDK 10.8 3rd-Party support link

FlashPlayer-10.6: Version: 11.9.900.152 - SDK 10.6 3rd-Party support link

QuickTime Plugin: Version: 7.7.1

AdobePDFViewerNPAPI: Version: 11.0.06 - SDK 10.6 3rd-Party support link

Flash Player: Version: 11.9.900.152 - SDK 10.6 Outdated! Update

AdobePDFViewer: Version: 11.0.06 - SDK 10.6 3rd-Party support link

o1dbrowserplugin: Version: 5.2.4.18058 3rd-Party support link

SharePointBrowserPlugin: Version: 14.0.0 3rd-Party support link

googletalkbrowserplugin: Version: 5.2.4.18058 3rd-Party support link

JavaAppletPlugin: Version: 14.8.0 - SDK 10.7 Outdated! Update

Safari Extensions:

Page Rank: Version: 1.0.0

AdBlock: Version: 2.5.55

Folx Safari Extension: Version: 1.0

Audio Plug-ins:

AirPlay: Version: 1.7 - SDK 10.8

iSightAudio: Version: 7.7.1 - SDK 10.8

iTunes Plug-ins:

Quartz Composer Visualizer: Version: 1.4 - SDK 10.8

User Internet Plug-ins:

CitrixOnlineWebDeploymentPlugin: Version: 1.0.105 3rd-Party support link

FolxNetscapePlugIn: Version: Unknown

Google Earth Web Plug-in: Version: 7.1 3rd-Party support link

3rd Party Preference Panes:

Flash Player 3rd-Party support link

Flip4Mac WMV 3rd-Party support link

Paragon NTFS for Mac ® OS X 3rd-Party support link

Old Applications:

Audacity: Version: 2.0.4.0 - SDK 10.4 3rd-Party support link

/Applications/Audacity/Audacity.app

Time Machine:

Time Machine not configured!

Top Processes by CPU:

9% mds

5% mdworker

4% WindowServer

2% EtreCheck

1% ps

Top Processes by Memory:

123 MB Google Chrome

90 MB Finder

78 MB WindowServer

78 MB Dropbox

61 MB Dock

Virtual Memory Information:

1.85 GB Free RAM

1.51 GB Active RAM

137 MB Inactive RAM

515 MB Wired RAM

353 MB Page-ins

0 B Page-outs