|If you don't know what you're doing it is best to stay out of system32 folder and do not delete anything.|
That said, my own DRVSTORE folder contains only one sub-folder associated with Windows Live Phone which I think is associated with Windows Live messenger. Total size is about 50kb so yours at 4.61mb is a whole lot larger. If you try to delete this folder you will probably be unable since it is a read-only folder, and if you do alter the attributes to allow deletion then you risk messing up something in windows that you night need at a later date. I would suggest scan with AV and if nothing is found leave it alone.
A little googling has revealed the blue lettering means the folder /file is either encrypted or compressed. Check the creation dates for each folder/file. Mine correspond with the date my operating system was installed. Anything more recent in yours may relate to software you have installeda various times. Any files with .inf suffix can be opened and read in notepad or wordpad. You should be able to identify what particular software they relate to.
Goin' Fishin' (Some day)