my computer is going slowly lately !

First, I recommend you run a temp files cleaner, such as CCleaner which is recommended above. Do make sure you turn off the registry cleaning component, as this could cause problems on your system. Second, I recommend you scan your machine for infection. There are over a dozen free online scanners available, but these three should get most (if not all) of it: http://www.trendsecure.com/portal/en-US/tools/security_tools/housecall http://www.ewido.net/en/ http://support.f-secure.com/enu/home/ols.shtml After you're done scanning, and if you find multiple infections on your system, it might be a good idea to beef up your security. Bare minimum, you should have antivirus, antispyware, and firewall with real-time protection. You can find a host of explanatory reviews on these and many other utilities here: http://www.techsupportalert.com/best_46_free_utilities.htm If you rarely install new software on your computer, you could achieve greater security by locking down the kernel, disabling access to the very attack surfaces malware target in order to run with Windows. There's more than one way to do this, but one way that works on most systems is here: http://invincible-windows.blogspot.com/

My laptop goes slow sometimes too. What I do is I try to reduce the load off my 'puter by closing all unnecessary software and deleting or transferring some files to my external drive. I scan it for viruses because these slow the pc. also, I try to use the AVG Anti-spyware because those "creatures" that connect to your pc unauhorized slow it down more than viruses do. Another thing is I use the registry fix and use the defragmenter of windows afterwards. When all else fail, I just format it but that's the final option.