Looking to upgrade this old M15X

what version of that model?  what current specs?  need more info then just since there is many variations of the m15x  

if  its a original m15x is best to ebay it..

but regardless  info above and what your plans are  on what you want to upgrade

I5 m450 @2.40ghz 2.40ghz   8G ram

General Information

Service Tag

Express Service Code  

Computer Model M15x

BIOS Vendor Alienware

BIOS Version A09

BIOS Date 1/5/2011

OS Version Microsoft Windows 7 Home Premium

Processor

Manufacturer Intel(R) Core(TM) i5 CPU M 450 @ 2.40GHz

Clock Speed 2.4Ghz

L2 Cache Size 256

Memory

Available Memory 67.85 %

Page File Size 16,359.2MB

Available Page File 100.00 %

Virtual Memory 16,359.2MB

Available Virtual Memory 81.86 %

M1 4,096.0MB

M2 4,096.0MB

Network controller

Storage

Drive C:

Type 3

Drive Size 465.7GB

Total Available Space 357.3GB

Used Space 108.3GB

Drive D:

Type 3

Drive Size 0.1GB

Total Available Space 0.1GB

Used Space 0.0GB

Drive G:

Type 5

Drive Size

Total Available Space

Used Space

Hardware

Type Description

DVD/CD-ROM Drives

MATSHITA BD-RE UJ235A

Disk Drives

Crucial_CT500MX200SSD1

Display Adapters

AMD Mobility Radeon HD 5800 Series

IDE ATA/ATAPI Controllers

Intel(R) 5 Series 6 Port SATA AHCI Controller

Ricoh SD/MMC Host Controller

Ricoh xD-Picture Card Controller

Ricoh Memory Stick Controller

Keyboards,Mice & Pointing Devices

Synaptics PS/2 Port TouchPad

HID-compliant mouse

HID-compliant mouse

Monitors

Generic PnP Monitor

Sound Devices

AMD High Definition Audio Device

IDT High Definition Audio CODEC

USB Controllers

Intel(R) 5 Series/3400 Series Chipset Family USB Enhanced Host Controller - 3B34

Intel(R) 5 Series/3400 Series Chipset Family USB Enhanced Host Controller - 3B3C

I suppose you could install a SSD (as bootable Windows).

Use it that way until you can acquire a new system.