Windows 7 Windows 7 takes forever to boot... and then the screen goes black once it does?!

Hey everyone,
You'll have to forgive me, I know a little about computers but not enough to solve a mess of my own problems o). I have a Lenovo laptop that I bought back in March, and though it is cheaply made, I have had little problems with it up until earlier this month. In early June, suddenly (literally, one day it happened just like that) when I would turn on my computer, Windows would take forever to boot. I mean 30 minutes, 20 if I was lucky. While this was a huge annoyance, the computer would run fine once it loaded and I use this computer for work so I didn't have much time to try to get it fixed. However, this morning I turn it on, and it takes as long as ever but with a new twist - once it does load, the screen goes completely black. I have no idea how this happened as I just loaded it yesterday and it was fine. Any suggestions would be great (please explain how to do things as you would to a 5th grader ).
GeneralOperating SystemWindows 7 Home Premium 32-bitCPU TypeIntel Pentium dual-core T4400(2.2GHz)Screen15.4" WXGAMemory Size3GB DDR2Hard Disk160GBOptical DriveDVD±R/RWGraphics CardIntel GMA 4500MVideo MemoryShared memoryCommunicationLAN and WLANBattery Life4.6 hoursDimensions14.10" x 10.10" x 1.22" - 1.46"Weight5.95 lbs.CPUCPU TypeIntel Pentium dual-coreCPU SpeedT4400(2.20GHz)CPU FSB800MHzCPU L2 Cache1MBDisplayScreen Size15.4"Wide Screen SupportYesDisplay TypeWide XGAResolution1280 x 800Operating SystemsOperating SystemWindows 7 Home Premium 32-bitGraphicsGPU/VPUIntel GMA 4500MVideo MemoryShared system memoryGraphic TypeIntegrated CardHard DriveHDD160GBHDD RPM5400rpm