There are several free solutions.
Uninstall any Internet Explorer toolbar. Most are unneeded, and may present serious safety holes and vulnerabilities. They also slow you down.
Look in the notification area.
ANY quick starter MUST be disabled. They become uterly useless 10 to 20 minutes after you have booted.
Also, disable any element that you don't realy need. You can probably un-install some/most/all of those.
Those can realy slow down your boot time and bog you down as you use your computer.
You probably need to perform a files cleanup.
CCleaner is an excellent, and free, product. It can safely find and remove most left over files.
it can also find and repair many errors and suppress most left over registry entries.
To be used before you use the other tools suggested.
Less files means less files to defragment, more room to perform the defragmentation and less files to scan for the anti-virus.
If documents and applications take to long to open, your drive is probably fragmented.
Fragmentation is a major slowdown source, in many cases, it's THE MAIN cause.
You need to defragment your drive(s). The speed disk provided with Windows is not good, and wont work if there is less than 15% free space, no mather how large is your drive. It will LOOK as if it's working, the graphic WILL change as if files are defraggmented, but there is NO optimisation done. If you have less than 10% free space, it will not even start working.
Try Defraggler. It does very good job and will work with as little as 1% free space.
If you are ready to pay for it, you should go for Disk Keeper. It's probably the best defragmenter you can get.
Get a good anitvirus like AVG or Avira. Both are available for FREE. Both are very good, and even beter than some paid AVs like McAfee and Norton.
Once installed, let it perform the suggested full system scan.
ANY AV that tells you that you are infected by more than 3 or 4 virus is probably a rogue AV of the scare-ware variety. These days, NO computer is ever realy infected by 20 or more virus at the same time. Most virus will try to kill any other virus to gain full use of your computer.
You should turn OFF most so-called "real time protection", or, at least tone it down. You realy don't need to scan all media files and doccuments as you open them.
By default, that kind of protection is usualy set way to aggessive.
Norton is infamous as a resources hog.
McAfee erroneously deleted several key system files due to a faulty deffinition update, destroying thousands of Windows installations.
Electro
January 2012