Open MSconfig disable everything except your antivirus.If you connect wirelessly then do not disable anything that reads wireless.REoot.You do not need anything other than your AV starting with your machine.http://netsquirrel.com/msconfig/index.htmlhttp://technet.microsoft.com/en-us/sysinternals/bb963902
unzip Autoruns to your desktop run it.See any entries that read file not found when you see them right click and select delete do this only for the entries that read file not found also uncheck any scheduled task that are set to run on your machine,close the program.
After completing the above task then Please download TFC by Old Timer and save it to your desktop.http://oldtimer.geekstogo.com/TFC.exe
Save any unsaved work. TFC will close ALL open programs including your browser!
double click on TFC.exe to run it.If TFC doesnt prompt a reboot then please do so manually
Hit start at the lower left hand corner type cmd in the run box and copy and paste the following info chkdsk /r Hit enter it will ask to schedule a check disk on the next reboot hit y type exit then reboot your machine it will take a good while to finish let it be this is normal.
You will need to open an elevated command prompt to run CHKDSK /R http://www.sevenforums.com/tutorials/783-elevated-command-prompt.html
Please download MINITOOLBOX and run it. Right Click Run As Adminhttp://download.bleepingcomputer.com/farbar/MiniToolBox.exe
Checkmark following boxes:
Report IE Proxy Settings
Report FF Proxy Settings
List content of Hosts
List last 10 Event Viewer log
List Installed Programs
List Users, Partitions and Memory size
Click Go and post the result.
Then defrag your machine. http://www.vcsoftwares.com/SpeeDefrag.html