Question : Windows file ID

1.  In the windows folder there exist three AU_X (where X is Backup, Log, and Temp) subfolders. Are these folders necessary? (temp is 30MB in size)
2.  There is the folder $hf_mig$ (139MB) What is it?  Is it necessary?
3.  There are about 45 folders named $NtUninstallKB...??...$ each about 3/4 MB  What are they? Are they necessary?
4.  There about 30 folders named $NtUninstallQ...??...$  What are they? Are they necessary

Answer : Windows file ID

The au_backup, au_log, etc. folders are from Trend-Micro Housecall antivirus.  See this page:

http://www.dslreports.com/forum/remark,12196350
Removing Trend Micro Housecall remnants