Full System scan started on second hard disk/didn't scan first?

Hello,

 

Tonight after experiencing a computer crash (that has been happening regularly for the past 3-4 months, pre and post re-format) I set a pc using NIS2011 doing a full system scan. Oddly it started on the second hard drive not the first which it usually starts on. It also did not scan the 'commonly infected and start up areas' as normal this time. Having gone away to let it finish I returned to have it say it had found nothing.

 

However, upon starting another full system scan (having done nothing else since the other one completed), it started as normal on commonly infected and start up areas, and then moved onto the first hard drive. This scan found 12 Tracking cookies.

 

Now whilst tracking cookies aren't much to worry about, the fact that the second scan found anything at all means the first scan only scanned the second hard drive.

 

To make it more confusing, the security history entry for the first scan, says it found 1 Tracking cookie, even though the end of scan report had said no threats found. Furthermore, the total items scanned for the first scan is, whilst considerably less than the second, not enough to mean an entire hard drive was skipped, suggesting it actually did both, yet seemingly missed 12 tracking cookies and 20,000 other files?

 

Items scanned:

Scan 1 scanned -

Total - 402,028

Files & Directories - 397,069

Registry Entries - 384

Processes & Start-Up items - 3,923

Network & Browser Items - 648

Other - 4

Trusted Files - 0

Skipped Files - 0

 

Scan 2 scanned -

Total - 428,907

Files & Directories - 424,263

Registry Entries - 384

Processes & Start-Up items - 3,610

Network & Browser Items - 646

Other - 4

Trusted Files - 0

Skipped Files - 0

 

This has never happened before and I really don't know what is going on here.

 

If anyone has some advice I'd appreciate it.