Starting with a virus scan always makes sense. If nothing is found then try the following:
Go to start>Run Type Prefetch then hit enter. A window will open, then press ctrl+A. Everything in the prefetch window should turn blue highlighted. Now Press Ctrl+D. You might get a confirmation window asking if you are sure you want to delete these xxxx items. Click yes, then after they’re all gone, close that window.
Right click the recycle bin. Select properties and then move the slider bar all the way to the left so that there is no disk space taken by it. Click Apply and then Ok.
Now go to Start>All Programs>Accesories>System Tools>Disk Cleanup. Chose the C: drive, then click yes to any warnings/Confirmations. Check all boxes when the disk cleanup window opens.
Go to The Start>Run>Msconfig>startup. Uncheck anything that’s not a firewall, anti-virus/spyware, sound drive, anything you need to run your computer properly, etc. Then click apply and close. It will ask to restart the computer. Go ahead and restart it.
When it starts booting, press F8 immediately until you get a screen that has a list of options. Select safe mode. Go to Start>All Programs>Accesories>System Tools>Disk Defragment. Then Select the C: Drive to defrag. This will take a while depending upon the size of the hard drive. Do not use the computer while it is running defrag. After it completes, restart the system like you would normally. After everything loads a window will pop up saying you have used the system config tool, check the box and click ok.
If you suspect your Internet or you think you might be broadcasting information over the Internet without your knowledge, run this
packet loss tool.