My vista laptop hangs on welcome screen I have files I need to access what should I do

Try booting to last known good configuration. Hit F8 a few times right after the BIOS screen and select that option. If that does not work, you can try Safe Mode.

Issue could be just a corrupt profile, could be a hard drive issue, maybe RAM, maybe a virus. Need to see if the system will startup at all first.

If nothing works, you can try a different RAM stick and do a full drive check. The BIOS may have an option to test hardware in it, or you can make a boot disk like Hiren's to run a disk scan.