What do you mean picking up? If someone built it for you, they better have installed and upgraded the system and tested it for ~24 hours. Should have no need to upgrade anything, that's why you paid extra, for them to do all that!
Yeah they are doing the 24 hour test hting and all that but you reckon they will update all the drivers as well hey? Oh well I guess I'll just check the driver versions when get it fired up and make sure they are all the latest ones.
good plan, let it run and work, and if something comes up, look for new drivers. The graphic card drivers are the ones that change the most, with the new cards being extra busy.
If you're using Vista, esp. x64, you need to be on the constant lookout for drivers. Most aren't very mature and there are lots of newer & better releases all the time.