Post upgrade problems

Just upgraded my Compaq from a 3.9Gb HD to an 89Gb Maxtor (I think) HD, and increased the RAM from 128 to 256.

Chap in the shop did advise that the pc, "as it's so old" may struggle to read the HD, but I thought i'd suck it and see. Anyhow all was well for a few days until yesterday when I turned the pc on, it refused to boot. The Compaq sign came up on the screen and that was it - the base unit did nowt.

I've been told to detach all leads, turn on and off a few times and reattach the leads but I don't see what difference this will make??!!!

Any idea's please? The PC has an Intel Pentium 4 processor but is not a new base unit.

 

What OS are running 98,95,nt etc.

What file system is it partitioned to fat16 fat32 ntfs

What type connection ata100,133 etc.

 

Sorry for the delay,

Windows XP Home Edition, Service Pack 2, Compaq pc - not sure of model.

The other questions went over my head a little I'm afraid. Simpler terms please!

The pc did let me go into in for about 5 mins yesterday then threw me out - it did bring up a blue screen with some error details for a few seconds then disappeared. Could it be a virus or internal problem?

I'm guessing that the pc is struggling to cope with the upgrade?