New PSU for optiplex 745?

[Farhan Shoaib]

Is there any psu that can fit in the low profile optiplex 745 that is 400-600 watts?

 

[Kisianik]

You mean Small Form Factor or Desktop (there is no Optiplex Slim)?
If yes, the answer is NO!
Dell is using proprietary power supply, small angled shape, so upgrade is almost impossible.

Before going any further, question to you - why do you need this upgrade?