You never responded to whether you did an inferior in-place Upgrade install or Clean Installed by booting the DVD and wiping the HD first as suggested.
Until you go fully clean with the install (you are in the install forum here) you will not have a best performance baseline to judge the rest by.
Make your Recover disks from recov partition or save a Windows 7 backup image, back up your files, gather you program installers, boot and wipe the HD using tutorial given earlier.
The installer is mostly driver
complete, with newer arriving quickly via optional Windows updates. Find any drivers
then missing in Device Manager on Support Downloads webpage for your model computer or device.
Install programs slowly over time to judge performance changes. Don't let any write themselves into msconfig>Startup as they become freeloaders on your CPU/RAM and can spy on you. I only allow AV and gadgets.
Use a lightweight free AV like MS Security Essentials with Windows Firewall.
Clean and order the HD perfectly with state-of-the-art free CCleaner and Auslogics Disk and Registry defraggers.
When you're done save a Windows 7 backup image so you never have to install again.