Everytime i attemp to launch fallout i get an error stating not enough free hard disk space fallout requires at least 20.0 megabytes of free hard disk space. This just started happening about a day after purchasing the game. heres my system info
Operating System: Windows Vista™ Home Premium (6.0, Build 6001) Service Pack 1 (6001.vistasp1_gdr.080425-1930)
Language: English (Regional Setting: English)
System Manufacturer: Acer
System Model: Aspire 9300
BIOS: PhoenixBIOS 4.0 Release 6.1
Processor: AMD Turion(tm) 64 Mobile Technology MK-38, ~2.2GHz
Memory: 766MB RAM
Page File: 1339MB used, 455MB available
Windows Dir: C:Windows
DirectX Version: DirectX 10
DX Setup Parameters: Not found
I would really appreciate some help

fixed itself

There's a very common bug with older applications - they store the free drive space in a 32 bit variable. However, such a variable cannot store numbers larger than 4Gb. The result is that if the actual free space is just over a multiple of 4Gb, the program will only see the excess. 20Mbs is a very small target, and windows will vary drive space quite a lot in normal operation as temporary files come and go, so its not surprising that it started working. If the problem comes back, simply adjust your free space so that its not close to a multiple of 4Gb.