Unsure of my system's security, help please!

Hello

 

I have recently hooked up a computer that I hadn't used for a long time: it's an XP machine with a Pentium 3Ghz processor and 1Gb of RAM. It's quite slow so I've spent a bit of time cleaning it up. I've installed the latest Norton Internet Security plus have cleaned/scanned my computer with Malawarebytes anti-malaware and CCleaner. I've also spent time uninstalling old programs and defragging the HD. The various scans returned the usual cookies but nothing sinister. However because my hard drive seems to be on the go most of the time I was concerned that this was a sign of an infection thus I used Norton Power Eraser and it returned 4 objects in the registry, one of which it resolved, the others it failed to fix. Can anyone give me some idea as to the likelihood of a problem with my computer?

 

Thanks, in advance, for your help

 

 

Driver1980