Forest stormed past QPR in stylish fashion, and will be glad of the distraction from their struggle to stay in the Championship.
The £4million-rated Reid was on top form for the visitors, scoring their first goal before Gregor Robertson made sure of their passage with an incredible 40-yard effort.
QPR keeper Chris Day's miserable afternoon was compounded by Forest's third, scored with eight minutes to go by Yoann Folly, but it took a massive deflection off team-mate Gareth Taylor to find the back of the net.
QPR lived up to the "teabag" label annually handed to them by boss Ian Holloway because they never stay long in the Cup.
Rangers have failed to make it past their first FA Cup match for the past four seasons, but they had more than enough opportunities to at least grab a draw against troubled Forest.
Reid started things off 24 minutes into the game with a free-kick that curled past Day after the striker went down just outside the area under a tackle from Danny Shittu.
Then Robertson made it two less than a minute later with a spectacular lob from just outside the centre circle after he spotted Day drifting off his line.
Kris Commons came within inches of scoring a third for Forest on the hour after he robbed Gareth Ainsworth only to slice wide of the post.
Rangers had started well and Jamie Cureton - up front for the suspended Paul Furlong - came close twice early on.
His first effort just two minutes into the game was parried by keeper Paul Gerrard and his second rattled the post.
But Reid had served notice of his danger 18 minutes into the match when he was left alone to shoot from just inside the area, forcing Day to palm the ball away for a corner.
Rangers, booed off the pitch at half time, had Forest camped in their own half for the first ten minutes following the break but could not convert the pressure into a goal.