Hi,
The below listed required for Installing SAP are:

1. NT Based operating (ex: Windows 2000,2003) is required 
or anyother Unix Operating System is required for 
Installing SAP.
2. HardDisk Capacity minimum required is 80GB recommended 
and maximum upto any extent in TeraBytes also.
3.There are 2 types of versions in SAP one is IDES and Non-
IDES.IDES Version is required by Functional Guys where one 
can see in Built T Codes and Non-IDES Version is for Basis 
Guys.

In three ways you can have SAP SOFTWARE in your computer. 
  
         1) Image cloning -Image restoring of an existing
installation (you need only          image files and 1 cd
software which will guide you one by one. NO TECHNICAL
KNOWLEDGE NEEDED) 
         2) Software fresh installation (for SAP ECC6 you
need 6 DVD, technical knowledge, installation steps with
screen shots etc) 
         3) Ready made Plug and ply SAP installed external
Hard disk. (You can connect 
          Preinstalled SAP hard disk to your machine and
start working SAP server) 
  
1) Image cloning. 

    I can help you for doing SAP Image restoring in to your
system. I can give you the Image files of SAP ECC 6.It's
very easy to restore. After restoring you'll get SAP IDS
SERVER working perfect with fine tuned functions. (We are
checking the each and every image files for its integrity) 
                   
Advantage of cloning :( image restores)
1) You can save time. Normally you can do it with in 1 hour
time where as normal installation will take 15 hours time!!
2) You’ll have a backup-copy ready with you .when SAP got
corrupted you can easily repeat the same you'll get back
your SAP server ready again.
3) You can do the installation to your friends also from the
same image files. 
4) You don’t need to know any extra technical things to do
this. You have to know how to restore the images which I'm
giving. 
                                 I'm using one powerful
licensed software for doing cloning .I can send you the
detailed screen shot of procedure. Just go through that
you'll come to know how to do that.
          You can do the installation later in your place
and make a huge profit out of this. Trust me)

2) Software fresh installation. 
                    If you are 100% confident that you can
do Software fresh installation by yourself; I can give you
the software and all the installation necessary steps with
screen shots .You need to get 15 hours to install this
software with out power cut!!. 
3) Ready made Plug and ply SAP installed external Hard disk 
                       I’ll install SAP Software for you in
an external hard disk and do all fine tuning and send to
you. You can plug this external hard disk in to your
computer and start working with SAP SERVER. I’ll buy brand
new hard disk for you and install SAP. 
If you are interested to learn multiple domains you can
customize SAP IDES installation. Suppose you are interested
in BI, MM, EP, SCM etc.You need to install SAP ECC 6 server,
BI severer and SCM server. I can install the SERVER software
according to your requirement from my place. After finishing
the installation I’ll cross check all the SAP transaction
codes and will fine tune the database. Then I remove the
hard disk from my computer and send to you. What you have to
do is you need to connect the hard disk in your computer and
boot from it. It’ll work just fine. 
                                              If you are
choosing this option you need to spend hard disk
cost+installation charges courier charges. 
                                   If you are interested in
SAP materials/software; send your updated postal address
(with full name, pin code, address and mobile number) to
sap.bnglr@gmail.com.(s a p . b n g l r @ g m a i l . c o m)
Don't forget to mention respective module (e.g.: SD, MM,
FICO etc)            
Thanks for the time you spend for reading this mail.  
Looking forward to hear from you soon.  

Warm Regards, 
sap guru

The following are the hardware configuration required for
installing SAP SERVER.
Configuration for SAP SERVER

FOR 4.7 E (old version) 

Hard disk 120 GB
Ram 1 GB
Processor P4


For ECC 6 (Latest version)

Hard disk : Minimum250 GB
Ram         : Minimum 2 GB
Processor : Minimum  Core 2 duo.

IDES version is good for a newbie.
OS :2003 EE.

SAP R/3 is System Application Products in DataProcessing 
and SAP all in one is the SAP Architecture where one will 
find Presentation,Application,DataBase Server in One SAP.

you need to check whether upgrade was successfully 
completer or not and then you need to check any backgrnd 
jobs are running on the system by using sm36,check whether 
any temse inconsistencies are present in your upgrade.