This could be a problem with the hard drive.  Run the Dell Diagnostics and see what is reported

 

http://docs.us.dell.com/support/edocs/software/DIAGS/EN/running.htm#starting_the_dell_diagnostics

 

http://support.dell.com/support/topics/global.aspx/support/dsn/en/document?c=us&dl=false&l=en&s=gen&docid=126A722713F6D0D0E0401E0A55174AE6&doclang=en&cs

 

To access them press F12 when you see the dell logo screen, then there will be an option that says IDE or Hard Drive Diagnostics. That will run a quick test, if you want a more thorough test select the option that says Boot to Utility Partition, then select custom test, select hard drive and then run test.

 

 

This article might help.

Tap F8 at the Boot Screen and select Restore to Last Good Configuration.

 

Dimension 9100, Dual-Boot Win XP / Vista Home Premium, 3.0 GHz P4, 3 GB DDR2 533 MHz RAM, 160 GB SATA II Samsung (XP), 300 GB SATA II Seagate (Vista), 250 GB SimpleTech USB (WD Drive), Nvidia Go 6800 (425/825 MHz - XP, 400/800 MHz - Vista, Vista Driver - 163.75), Dell 1901 UltraSharp FP

Inspiron E1705, Win Vista Premium, T7200 Core 2 Duo (4MB, 2.0 GHz 667MHz), 2 GB DDR2 677 MHz RAM, 120 GB Samsung HD, Nvidia Go 7900 GS - 156.69 Driver, 17” Sharp UltraSharp TrueLife Wide-Screen WUXGA

I DONT UNDERSTAND i did this stuff BUT STILL IT DOESNT WORK my computer is alreadys installed with vista but it get stucks when i try to load up the computer I CANT EVEN GET TO Logging IN i get to the part where it says microsoft coporation and a green bar is moving and it freezes even when i try to do safe mode it freeses at crcdisk.sys and when trying to work restore mode IT FREEZES i need help I DONT WANT TO REFORMAT plz note my computer is a sony

You will have to go to a Sony support forum. We are Dellites.

 

Dimension 9100, Dual-Boot Win XP / Vista Home Premium, 3.0 GHz P4, 3 GB DDR2 533 MHz RAM, 160 GB SATA II Samsung (XP), 300 GB SATA II Seagate (Vista), 250 GB SimpleTech USB (WD Drive), Nvidia Go 6800 (425/825 MHz - XP, 400/800 MHz - Vista, Vista Driver - 169.25), Dell 1901 UltraSharp FP

Inspiron E1705, Win Vista Premium, T7200 Core 2 Duo (4MB, 2.0 GHz 667MHz), 2 GB DDR2 677 MHz RAM, 120 GB Samsung HD, Nvidia Go 7900 GS - 156.69 Driver, 17” Sharp UltraSharp TrueLife Wide-Screen WUXGA