If your Optus program is writen in Java then you have "Java problem" as HC is Java as well. Java and MS-Outlook is the most frequently attacked spots by viruses/hackers.
Scanning for viruses is fine as long as it is not resident, you invoke it and terminate it - then it's fine, if it is resident then it is not YOU who controls the machine (I'm hardly against resident a-virus).
Defrag will give you same problem just maybe better alligned.
History too big is Fairy Tail and Temp Int Files doesn't matter too much also it's good to delete it from time to time.
If you running out of space memory/hard disk/resources your machine will tell you and/or it will become very slow but HD will work very hard (swap file) so you should notice it immediately.
The approach I take is :format/ install/tune then enjoy it as long as it takes.(Fast/clean machine, all private data stored on D: drive (physically separate/ scan before store but still even if it is infected it will more affect C: / programs).
Anything goes wrong then format/ install/tune on C: drive. With the CD-Rom now it's a breeze, no shuffling of floppies for hours).
Last my interval was 3.4 years. Antivirus BS is just to make some rich. Yes it's nasty viral environment but the cure is quick so all you have to learn is how to REBUILD YOUR MACHINE and keep your personal data S E P A R A T E, always backed up.
Your C: drive should be treated as an temporary means to boot cleanly your machine/system, any suspitions then wrecklesly REBUILD IT, so learn it quick how to do it.
Happy re-building.
Or take "MORE SPEED" like BK so you will notice NO diference (hey, just kidding now).
