Bruce: Funny too see all those answers while there isn't even any background information about the problem.
Yelling 'how do i speed up my computer' can be interpreted in many ways.
But to keep it simple:
If you really need a fast computer there's no other solution than to make sure you have some decent hardware running.
Second is to keep your system clean and safe with a light firewall and antivirus. (For example Comodo Free and Bitdefender Free)
Clean your temporary files, browser history and downloads regularly using CCleaner Free edition.
STAY AWAY FROM MALICIOUS WEBSITES!
Don't have too much stuff installed on your system (and always check new install packages for Browser toolbars and stuff since you really don't want to have those!)
One thing you could do to prevent yourself from hours of useless work is to get your system installed FRESHLY and ONLY install the things you use regularly AFTER installing all drivers.
Then, make sure your installation has all the recent available OS updates installed.
When done, make a windows backup copy and store it on a secondary partition or external disk.
Now whenever your system is crashed or you need to reinstall, all you have to do is reinstall windows (don't forget to format your OS partition) and restore the backup copy.
Worst thing that could happen now is that you might need to install some additional updates and program updates.
You can always make another backup copy after restoring a backup and updating it.
This way you will always be spared a lot of boring work which only takes time!
Install Linux Mint. Linux doesn't need antivirus
1.) delete temp files. (enter this in run -%temp%) and delete all files.
2.)install good antivirus
3.)download and install AVG PC tuneup 2015 that would be better to maintain ur computer performance.
reinstall windows. Seriously, just back up only things you need and do a factory restore
add new RAM in you system and also scan your computer with a good antivirus
add another hard disk drive.. sometimes you can add 2 3 or 4 hard disk drives the better