One thing that many people don't realize is that virus scanners (for the most part) only detect known virii/malware.
If I write a trojan from scratch and roll it into a utility program (register cleaner for example), no virus scanner in the world is going to emit a peep when it scans it.
On the plus side, the majority of malicious folks out there couldnt write a trojan, they just take existing code and re-use it, re-package it.
However my point is this, just because your virus scanner says that something is "clean" all that means is that it did not detect the signatures of any known malware. It doesn't mean that it is clean.
Another point I'd like to make is that programs like defragmenters and registry cleaners have the very real possibility of trashing your system if they are buggy (unlike most apps whose bug's damage is limited to just the files that the app works with directly)
There are a couple of good mainstream defragmentation products out there in addition to the free version that comes with windows. Stick with them. The benefits of defragmentation are overstated for most people with typical disk access needs.
Registry cleaners pray on people's mental image that a PC with a lot of left over crap in the registry are slowed down a lot by it. By in larger that is false. The PC doesn't read registry entries that aren't used - registry entries are read when a specific program needs to access to it.
The risk of deleting something that is actually needed far outweighs the potential slight performance benefits of registry cleaning.
If you have abused your machine with so many software installs/uninstall that you think it needs "cleaning" then its time to just bite the bullet and do a fresh OS install - can't get any cleaner than that.
If I write a trojan from scratch and roll it into a utility program (register cleaner for example), no virus scanner in the world is going to emit a peep when it scans it.
On the plus side, the majority of malicious folks out there couldnt write a trojan, they just take existing code and re-use it, re-package it.
However my point is this, just because your virus scanner says that something is "clean" all that means is that it did not detect the signatures of any known malware. It doesn't mean that it is clean.
Another point I'd like to make is that programs like defragmenters and registry cleaners have the very real possibility of trashing your system if they are buggy (unlike most apps whose bug's damage is limited to just the files that the app works with directly)
There are a couple of good mainstream defragmentation products out there in addition to the free version that comes with windows. Stick with them. The benefits of defragmentation are overstated for most people with typical disk access needs.
Registry cleaners pray on people's mental image that a PC with a lot of left over crap in the registry are slowed down a lot by it. By in larger that is false. The PC doesn't read registry entries that aren't used - registry entries are read when a specific program needs to access to it.
The risk of deleting something that is actually needed far outweighs the potential slight performance benefits of registry cleaning.
If you have abused your machine with so many software installs/uninstall that you think it needs "cleaning" then its time to just bite the bullet and do a fresh OS install - can't get any cleaner than that.