Please help dvd/cd-rom drive won't work

Question

When I start computer the dvd/cd-rom drive is seen and works under  my computer (listed under other) but after an couple of minutes the drive has an red x and is listed as cd drive. There are times when it doesn't show up period. When I go under device manager I see and yellow exclamation mark. I cannot roll back (icon doesnt allow) and when I try to update it says that this version is the most update version. I have never personally tried to update this driver since I bought the computer it seems as if overnight there is a problem.
When I go to device manager and go to properties the message that appears is:  Windows cannot load the device driver for this hardware because a previous instance of the device driver is still in memory. (Code 38)
I have a lenovo G575
AMD E-350 processor 1.60 GHz,
RAM 3.00 g.b.,
Windows 7 64bit operating system.
I have tried to use the troubleshooting tool but it doesn't work.
Could someone give me step by step instructions on how to fix my computer.
Thankyou in advance.

Answer 1

When you go to device manager for the device right click the drive and click Uninstall,AFTER and only after you do that download the correct driver from Lenovo's website and then install it.  It is generally best to totally uninstall old drivers before attempting updating to a new/different one as it can create issues like this.  Let me know if this worked for you.
Lenovo 15.6,B575 W7 E-450,ATI6320,320GB,8GB DDR3 Ram-*Midnight*
Dell Latitude D430,12.1 C2D 1.3 ULV,2GB DDR2,80gb SSD,Intel 950,XP *Mini Me*
Dell Latitude D630,14.1,C2D2.0,W7,500GB,8GB DDR2,X3100*Old Faithful*
Nvidia I shall Never forgive you for the 8000m Series.