lappy not booting right

Our laptop wouldn't boot properly this morning: the start menus etc didn't load onto the screen, so we were left with just the background. We did managed to open Task manager, and that didn't show any different from normal, but we couldn't start any programs. We took the battery out, because it was boiling hot, and leaving it plugged into mains, tried to boot up again. this time we got start menus and icons as normal, but these disappeared again after a short while :confused

it worked fine yesterday, but i don't know if it got turned off properly as my bro was using it. I have managed to get it to boot in safe mode (with out battery), but now what?

it won't open IE, so i tried MS Word and got:
'Set up Error
A Required
C:\DOCUME~1\ADMINI~1.MAP\LOCALS~1\Temp\Setup00000548\OSSETUP.DLL cannot be loaded.'

laptop= dell latitude D505
battery=dell C1295
OS= WinXp Sp3

I'm happy to give any more info, just shout

 

safe mode *tick*
add/remove progs *tick*
MS office click 'change'
'Please wait while Setup prepares the files' then the new window closes itself, and i'm left with the add/remove programs list again

normal mode still leaves me without icons, and start menus

 

right-o, will start this now, but i'm going out in about half an hour, so will continue later (about 7ish). i'll be as speedy as i can.

ps. the malware steps could prove difficult seeing as i have no internet on there, i'll try the flash drive method...

thanks

edit: it seems normal mode gives me the start toolbar, but it doesn't work, and it won't load task manager

 

results:
1. no. it doesn't like this anymore :confused
2. 'Uninstall did not complete sucessfully' :$ ran ccleaner anyway, it seemed to remove quite a bit
3. minor panic over... run wasn't on the menu :confused... then it was reboot in normal mode, and it didn't make a difference

 

have managed to get SAS up and running, ZZzzzzz :zzz two and a half + hours later... will run the rest of the antimalware at grandmas tomoro :banghead

 

uh oh... was moving the sas logs to memory stick this morning and got the blue screen of death followed by lots of clicking from the hdd :confused it turned off, and when i tried to restart the clicking continued through the dell start-up screen, then stopped and the laptop announced 'no bootable drive'. when we got home, i took it apart and the hdd rattles (is this normal?) it seems to be a terminal condition, do you agree?