Trojan from AVG AntiSpyware

When I downloaded AVG Anti-spyware from grisoft site it said there was a trojan horse c:\docume~1\owner\locals~1\temp\nstB.tmp\installoptions.dll

I told it to heal, but it still popped up when Iinstalled the program. I looked online and many people report similar things. people speculate it was a false positive. What do you suggest I do to check this to ensure i don't have this trojan.

my scans are coming back clean so far.

Dewayne