Probably normal,
These are done during normal maintainance, when you or windows updates files or have had to correct errors on the drive. The only time that you should worry is if they also show as infected..
Even though yours is different its probably the same principle since you reformatted and installed avg av it updated.
As you see in the link you have the option to prevent this.
Tom
Ok, recently i reformated my hard drive. I have a AMD athlon 64 3500, running windows Xp sp2. with IE7 and run the free AVG newest version. every things seems to work great, but when i run the virus scan with AVG, it shows no viruses, but shows my ntoskernel/win32 and now it show another thats just kernel/win32 but it says change. not infected. what should i do, or can i fix it or change those 2 files some how with out reformating it.?? and how did it infect those files?? It can't be from my windows disk, must have happened after installing, from some where. Danny
Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic