The main reason for what you report is the factory bloatware which is all running by default to slow the computer to a grind.
The macro solution to this is to borrow or obtain a clean-copy Win7 installer of your version to clean reinstall with the Product Key on your COA sticker. Don't expect any help from Sony with this as all maker's enforce their bloatware now to protect slim profit margins.
But until you are ready for that, there are some immediate fixes:
Type msconfig in Start search box, rightclick Run as Admin, click on Startup Tab and uncheck everything except AV and sidebar gadgets. Nothing else needs to startup until you click it.
Install free Revo Uninstaller and using Advanced mode remove any bloatware you don't want. It will run the Windows uninstaller for you, but don't restart when prompted until you click Next to delete all the (bolded) leftover Registry keys and files it finds for you to Delete.
Most important is to uninstall any paid Anti-Virus bloatware using Revo and use instead free Microsoft Security Essentials which installs in 30 seconds, updates and runs a quick scan then becomes invisible with no impact on your system until it finds a threat.
Check the Event Viewer>Admin View to google repeat errors for solutions which keeps your thumb on the pulse. Run sfc /scannow to find and fix any System Files corrupted by bloatware or its removal.
Finally, clean and order your HD perfectly by installing and running state-of-the-art free CCleaner ("Run Cleaner" and Registry tab) then Auslogics Disk and Registry Defraggers monthly.
Report back how this regimen works for you, and any questions about the clean reinstall which now is actually better than gettin a new computer as you can see.
