Need expert laptop help!

[Micachaly]

Hi I have the following laptop,

Dell XPS 17: Intel i7-2720QM (2.2GHz) Mobile CPU
17.3in FHD 3D WLED TL (1920X1080) 1080p
NVIDIA GeForce GT 555M 3GB graphics (3D Capable)
14GB (3x4Gb + 1x2Gb) 1333MHz DDR3 Dual Channel
1TB (2x500Gb) Serial ATA (7200RPM) Dual HDD

startup is sluggish and when i play games eg deus ex - it sometimes lags and is not smooth.
done hardware tests and all is good and the temperature's seem fine
any ideas how to correct this issue?

 

[Ubrales]

Check start-up programs. Do not have too many programs in your start-up folder.

Next, check disk fragmentation, and defrag if necessary.

Download and run "CCLEANER"

Get rid of Dell crap - download and run "Decrapifier"

 

[Pyree]

Try lower the settings. GT555m is not strong. Recommend GPU is an AMD 5850 and the GT555m is performing somewhere between a 5670 and 5750.