hi have a look at some of these

http://www.google.co.nz/search?hl=en&q=how+to+apply+thermal+paste&btnG=Google+Search&meta=

also not sure if a 3.8ghz cpu will work in a 2400 look here
http://support.dell.com/support/edocs/systems/dim2400/en/sm_en/specs.htm


Dimension 8300,
P4 2.80GHz 800MHz w/HT
1GB PC3200
Sparkle 6600GT OC
Creative SB Audigy 2 ZS (retail)
Leadtek DV2000 tv tuner,
Seagate SATA 120,160, USB2 external 200GB
NEC DVD+RW ND-2100AD, Pioneer 16x DVD+/-RW DL DVR-109,
Dell E152FP 15 inchs LCD
D-link DSL-G604T Router & D-link DWL-G122 wireless adapter
HP deskjet 3550, HP PSC 1310 all in one
Wacom graphire3 4x5inch, PCI Cooler | 80mm hdd fan
Benchmarks 3dmark03 8446...3dmark05 3498..3dmark06 1821...PCmark05 3448

You won't need thermal paste at all - that CPU will not run on a 2400 system.

The max for the 2400 is a 3.06/533/512K - the 3.8 is an 800 MHz CPU and won't work with a 2400.

What's a 3.8 GHz Northwood Processor?   I thought that the 3.4GHz Northwood C Model that I bought in early 2004 was the largest Northwood made.

 

 

Pentium 4 660 @ 3.6 GHz. 2MB L2 Cache 64 bit 800 FSB HT.
Intel 945G. MB. ---- 2 Gigs Samsung PC 4200 DDR2 533 MHz.
W.D.160 Gig. 7200rpm 8 mb cache HD. ---- S.B. Audigy 2 ZS.
Floppy & 16X DVD Rom. and Dual Layer DVD & CD Burner.
XP Professional & Office XP Pro. 2003 Edition.
eVGA 7900 GT CO Superclock @ 590/1750.
OCZ Modstream 520 Watt PSU---Gateway FPD1975 LCD(8ms)
Logitech Z-3 2.1 Speakers---Belkin Nostromo N52 Speedpad
Logitech MX 518 Gaming Mouse----Func 1030 Gaming Surface.
Logitech Momo Racing Wheel & Pedals
3dMark06----- 5032
http://service.futuremark.com/compare?3dm06=333978

Sorry for the 3.8 thing its a 3.06. anyway thanks for the posts.